1.1.7: Comparing Biological Macromolecules
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What you’ll learn to do: Discuss macromolecules and the differences between the four classes
As we’ve learned, there are four major classes of biological macromolecules:
- Proteins (polymers of amino acids)
- Carbohydrates (polymers of sugars)
- Lipids (polymers of lipid monomers)
- Nucleic acids (DNA and RNA; polymers of nucleotides)
Let’s take a closer look at the differences between the difference classes.
Learning Objectives
Distinguish between the four classes of macromolecules
Carbohydrates are a group of macromolecules that are a vital energy source for the cell, provide structural support to many organisms, and can be found on the surface of the cell as receptors or for cell recognition. Carbohydrates are classified as monosaccharides, disaccharides, and polysaccharides, depending on the number of monomers in the molecule.
Lipids are a class of macromolecules that are nonpolar and hydrophobic in nature. Major types include fats and oils, waxes, phospholipids, and steroids. Fats and oils are a stored form of energy and can include triglycerides. Fats and oils are usually made up of fatty acids and glycerol.
Proteins are a class of macromolecules that can perform a diverse range of functions for the cell. They help in metabolism by providing structural support and by acting as enzymes, carriers or as hormones. The building blocks of proteins are amino acids. Proteins are organized at four levels: primary, secondary, tertiary, and quaternary. Protein shape and function are intricately linked; any change in shape caused by changes in temperature, pH, or chemical exposure may lead to protein denaturation and a loss of function.
Nucleic acids are molecules made up of repeating units of nucleotides that direct cellular activities such as cell division and protein synthesis.  There are two types of nucleic acids: DNA and RNA.
Practice Questions
Explain at least three functions that lipids serve in plants and/or animals.
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Fat serves as a valuable way for animals to store energy. It can also provide insulation. Phospholipids and steroids are important components of cell membranes.
Explain what happens if even one amino acid is substituted for another in a polypeptide chain. Provide a specific example.
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A change in gene sequence can lead to a different amino acid being added to a polypeptide chain instead of the normal one. This causes a change in protein structure and function. For example, in sickle cell anemia, the hemoglobin β chain has a single amino acid substitution. Because of this change, the disc-shaped red blood cells assume a crescent shape, which can result in serious health problems.
Check Your Understanding
Answer the question(s) below to see how well you understand the topics covered in the previous section. This short quiz does not count toward your grade in the class, and you can retake it an unlimited number of times.
Use this quiz to check your understanding and decide whether to (1) study the previous section further or (2) move on to the next section.
Contributors and Attributions
- Introduction to Comparing Biological Macromolecules. Authored by : Shelli Carter and Lumen Learning. Provided by : Lumen Learning. License : CC BY: Attribution
- Revision, adaptation, and original content. Authored by : Shelli Carter and Lumen Learning. Provided by : Lumen Learning. License : CC BY: Attribution
- Biology. Provided by : OpenStax CNX. Located at<EMAIL_ADDRESS>. License : CC BY: Attribution . License Terms : Download for free at<EMAIL_ADDRESS>- Biological Molecules - You Are What You Eat: Crash Course Biology #3. Authored by : Crash Course. Located at : https://youtu.be/H8WJ2KENlK0 . Project : Crash Course Biology. License : All Rights Reserved . License Terms : Standard YouTube License


3.2: Exercises
Exercise A: How Penicillin Was Discovered
In 1928, Sir Alexander Fleming was studying Staphylococcus bacteria growing in culture dishes. He noticed that a mold called Penicillium was also growing in some of the dishes. A clear area formed around the mold, indicating that the bacteria in this area had died. In the culture dishes without the mold, no clear areas were present. Fleming hypothesized that the mold must have produced a chemical that killed the bacteria. He decided to isolate the substance and test it to see if it would kill bacteria. Fleming transferred the mold to a nutrient broth solution. This solution contained all the materials the mold needed to grow. After the mold grew, he removed it from the nutrient broth. Fleming then transferred some of this broth onto a culture of bacteria. He observed that the bacteria died. This finding was later used to develop the first antibiotic, penicillin, which was used to treat a variety of bacterial diseases.
Exercise B: Identify the Controls and Variables
1. Muhammad thinks that a special juice will increase the productivity of workers. He creates two groups of 50 workers each and assigns each group the same task (in this case, they're supposed to staple a set of papers). Group A is given the special juice to drink while they work. Group B is not given the special juice. After an hour, Muhammad counts how many stacks of papers each group has made. Group A made 1,587 stacks; Group B made 2,113 stacks.
2. Sophia notices that her shower is covered in a strange green slime. She reads on social media that coconut juice will get rid of the green slime. Sophia decides to test this claim by spraying half of the shower with coconut juice. She sprays the other half of the shower with water. After three days of "treatment" there is no change in the appearance of the green slime on either side of the shower.
3. Anh was told that a certain anti-itch cream was the newest and best one on the market: it claims to reduce itching 50% longer than the leading brand. Interested in this product, she buys the anti-itch cream and compares it to her usual product. She finds two subjects that have itchy mosquito bites. Test subject A applies the original anti-itch cream, and test subject B applied the new anti-itch cream. Subject A reported their itching returned after two hours. Subject B reported their itching returned after one hour and 45 minutes.
4. Lisa is working on a science project. Her task is to answer the question: "Does Rogooti (which is a commercial hair product) affect the speed of hair growth". Her family is willing to volunteer for the experiment.
The Introduction, Exercise A, and Exercise B are adapted from the following:
Burran, Susan and DesRochers, David, "Principles of Biology I Lab Manual" (2015). Biological Sciences Open Textbooks. https://oer.galileo.usg.edu/biology-textbooks/3(opens in new window)
Part of the Biology Commons. Follow this and additional works at: https://oer.galileo.usg.edu/biology-textbooks
This Open Textbook is brought to you for free and open access by the Biological Sciences at GALILEO Open Learning Materials. It has been accepted for inclusion in Biological Sciences Open Textbooks by an authorized administrator of GALILEO Open Learning Materials. For more information, please contact<EMAIL_ADDRESS>.
Exercise C: Reporting Scientific Work
C.1 What is a primary reference?
C.2 Name two peer-reviewed scientific journals in the field of Biology.
C.2 Use the internet to find a peer-reviewed journal article related to cell and molecular biology. Then, in your own words, write a summary of the research (1-2 paragraphs). Include the full reference citation.
Exercise D: Designing an Experiment
We will split the class data into two groups, those that we consider to be athletic and those that are not. We want to know if athletic individuals have lower resting pulse rates than nonathletic individuals. For our lab study, we will consider athletic individuals to be anyone that exercises three hours a week, or more. Lastly you will make a graph of the class data and evaluate your hypothesis (supported or falsified).
D.1 Create a testable hypothesis.
D.2 Create a prediction ( if your hypothesis is true, then what results do you expect?).
Data collection: Each student will measure their pulse rate ten times and calculate the average. Be sure to be seated and calm for at least ten minutes prior to taking your pulse. Record your data in the table below and share your average with the class.
D.3 What are the controlled variables in our experiment?
D.4 What is the control group?
D.5 What is the level of treatment?
| Measurement | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
|---|---|---|---|---|---|---|---|---|---|---|
| Beats per 15 seconds | ||||||||||
| Beats per minute |
Table 1. Individual Resting Pulse Rates
D.6 What is your average resting pulse rate in beats per minute (bpm)? _________ Place your average resting pulse rate onto the white board, make sure you correctly assign yourself as an athlete or non-athlete.
D.7 How many students are in the class? _______ How many students are athletic? ______ How many students are not athletic? ________
D.8 Copy the class information into the table below and calculate the class averages.
|
Athletic |
Nonathletic |
|
|---|---|---|
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List of individual pulse rate averages (bpm) |
||
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Class average (bpm) |
Table 2. Summary of Class Data: Resting Pulse Rates of Athletic and Nonathletic Individuals
D. 9 What was the independent variable for our experiment? On which axis would you graph this?
D.10 What was the dependent variable for our experiment? On which axis would you graph this?
D.11 Design a graph that shows the relationship between the dependent and independent variables in the experiment. Should you use a line graph or a bar graph? Remember to give the graph a proper title, label your x-axis and y-axis, and include their units. Use a separate sheet of paper and staple it to this lab.
D.12 Drawing conclusions: Does the data support your hypothesis?
Exercise E: Design Your Own Experiment
During exercise muscle metabolism increases, resulting in an increase in the production of CO 2 . Interestingly, however, our blood levels of CO 2 do not change significantly during exercise because the increased rate in CO 2 production is matched by a greater rate of CO 2 elimination by the body (respiratory rate and depth increase during exercise). The equation below describes how CO 2 is transported through the blood and is important in the study of respiration and acid-base balance.
CO 2 + H 2 O --> H 2 CO 3 --> H + + HCO 3 -
First, read the procedure. Then, complete the Experimental Design section below. After completing the experiment, record and explain your results.
A. Procedure:
- Fill a 250 mL beaker with 200 mL of distilled water and add 5.0 mL of 0.10N NaOH and one or two drops of phenolphthalein indicator (turns pink in alkaline solutions; is clear in neutral/acidic solutions). Mix well and pour half of this solution into a 150 mL beaker (save this for later).
- Select one student in your group to volunteer for this experiment. This student’s results will be examined at rest and after 2-5 minutes of vigorous exercise.
- Student: sitting quietly, exhale through two straws into the solution in the 250 mL beaker. Cover the beaker with a paper towel to avoid splashes. Be careful NOT to inhale or drink the solution . Group members: record the time required to turn the solution from pink to clear.
- Time at rest (pink to clear): _____________________________
- Discard this first solution. Pour your saved solution from the 150 mL beaker into the 250 mL beaker, replace the two straws and cover with a paper towel.
- Student: exercise vigorously with your group members for 2-5 minutes (find a safe and clear area outside of the lab room to do jumping jacks, etc. Heart rate and breathing rate should be increased.)
- Student: repeat step 3 immediately after exercise (before your heart rate and breathing rate return to normal). Be careful NOT to inhale or drink the solution . Group members: record the time required to turn the solution from pink to clear.
- Time after exercise (pink to clear): _____________________________
- Discard the solution and straws. Rinse and replace the glassware.
B. Experimental Design:
Question: _________________________________________________________________________
Testable hypothesis: ________________________________________________________________
Dependent variable: ________________________________________________________________
Independent variable: _______________________________________________________________
Controlled variables: _________________________________________________________________
Control: ___________________________________________________________________________
Level of treatment: __________________________________________________________________
Replication: ________________________________________________________________________
Prediction (if/then): _________________________________________________________________
__________________________________________________________________________________
C. Do your results support or refute your hypothesis? Explain your findings below:


3.19: Introduction to Other Internal Communications
What you’ll learn to do: Identify other common methods of professional communication
Where do email chains and LISTSERVs fit in to professional business communication? Can SMS text messages and Instant Messaging be used for professional purposes? What multimedia platforms are important today and provide value for the business professional?
Contributors and Attributions
CC licensed content, Original
- Introduction to Other Internal Communications. Authored by : Robert Danielson. Provided by : Lumen Learning. License : CC BY: Attribution
CC licensed content, Shared previously
- email newsletter. Authored by : ribkhan. Provided by : Pixabay. Located at : pixabay.com/en/email-newsletter-marketing-design-3249062/. License : Public Domain: No Known Copyright


2.7: Popular Culture: Rationality and Perfect Information
In this section, we will look at applications of rationality and perfect information in popular culture. We present films with connections to game theory and suggest some related questions for essays or class discussion.
The movie Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb (\(1964\)) depicts the cold war era with the USA and the Soviet Union on the brink of atomic war.
Society would generally consider General Jack Ripper to be irrational. What is his goal or his optimal payoff? Give evidence that he is, in fact, acting rationally in light of his goal.
Explain how the Soviet's Doomsday Machine is supposed to be the ultimate deterrent to nuclear war. How does the lack of perfect information impact the effectiveness of the Doomsday Machine?
In the movie The Princess Bride (\(1987\)) the Dread Pirate Roberts and kidnapper Vizzini engage in a battle of wits in which Vizzini is to deduce which goblet contain a lethal poison.
In your own words describe how the poison scene demonstrates that knowing that both players have the same knowledge can help one deduce additional information. In other words, just knowing that one player has all the information is not enough; that player, must also know that the other player has the same knowledge.
Of course, in the poison scene, both players break the rules. How does this impact the players' ability to use perfect information?
Now try to apply the ideas of rationality and perfect information to your own popular culture examples.
Consider a game-theoretic scenario in a novel or film of your choice. Are the players rational? What are the players' goals, and are they making choices which will maximize their payoff? Explain.
Consider the statement “One of the main differences between horror films and suspense films is that in horror films characters behave irrationally while in suspense films they behave rationally.” Do you agree or disagree with this statement? Give an example of a suspense film and a horror film with evidence from the films that supports your position.
Think of other films where two characters engage in a “game.” What are the assumptions of the players? Do they have perfect information? Does the amount of information a player has give him or her an advantage? Explain.
Give an example from a film, current events, or your own life where if one player “breaks the rules,” while the other player assumes perfect knowledge (both players know the possible strategies and outcomes), it will change the outcome of the “game.”


1.5: Macroeconomics- The Big Picture
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4. How do economic growth, full employment, price stability, and inflation indicate a nation’s economic health?
Have you ever looked at CNN’s Headline News on a mobile device or turned on the radio and heard something like, “Today the Labor Department reported that for the second straight month unemployment declined”? Statements like this are macroeconomic news. Understanding the national economy and how changes in government policies affect households and businesses is a good place to begin our study of economics.
Let’s look first at macroeconomic goals and how they can be met. The United States and most other countries have three main macroeconomic goals: economic growth, full employment, and price stability. A nation’s economic well-being depends on carefully defining these goals and choosing the best economic policies for achieving them.
Striving for Economic Growth
Perhaps the most important way to judge a nation’s economic health is to look at its production of goods and services. The more the nation produces, the higher its standard of living. An increase in a nation’s output of goods and services is economic growth .
The most basic measure of economic growth is the gross domestic product (GDP) . GDP is the total market value of all final goods and services produced within a nation’s borders each year. The Bureau of Labor Statistics publishes quarterly GDP figures that can be used to compare trends in national output. When GDP rises, the economy is growing.
The rate of growth in real GDP (GDP adjusted for inflation) is also important. Recently, the U.S. economy has been growing at a slow but steady rate of between 3 and 4 percent annually. This growth rate has meant a steady increase in the output of goods and services and relatively low unemployment. When the growth rate slides toward zero, the economy begins to stagnate and decline.
One country that continues to grow more rapidly than most is China, whose GDP has been growing at 6 to 7 percent per year. Today few things in the global marketplace are not or cannot be made in China. The primary contributor to China’s rapid growth has been technology. For example, most tablets and laptops are manufactured in China.
The level of economic activity is constantly changing. These upward and downward changes are called business cycles . Business cycles vary in length, in how high or low the economy moves, and in how much the economy is affected. Changes in GDP trace the patterns as economic activity expands and contracts. An increase in business activity results in rising output, income, employment, and prices. Eventually, these all peak, and output, income, and employment decline. A decline in GDP that lasts for two consecutive quarters (each a three-month period) is called a recession . It is followed by a recovery period when economic activity once again increases. The most recent recession began in December 2007 and ended in June 2009.
Businesses must monitor and react to the changing phases of business cycles. When the economy is growing, companies often have a difficult time hiring good employees and finding scarce supplies and raw materials. When a recession hits, many firms find they have more capacity than the demand for their goods and services requires. During the most recent recession, many businesses operated at substantially lower than capacity. When plants use only part of their capacity, they operate inefficiently and have higher costs per unit produced. Let’s say that Mars Corp. has a huge plant that can produce one million Milky Way candy bars a day, but because of a recession Mars can sell only half a million candy bars a day. The plant uses large, expensive machines. Producing Milky Ways at 50 percent capacity does not efficiently utilize Mars’s investment in its plant and equipment.
Keeping People on the Job
Another macroeconomic goal is full employment , or having jobs for all who want to and can work. Full employment doesn’t actually mean 100 percent employment. Some people choose not to work for personal reasons (attending school, raising children) or are temporarily unemployed while they wait to start a new job. Thus, the government defines full employment as the situation when about 94 to 96 percent of those available to work actually have jobs. During the 2007–2009 recession in the United States, the unemployment rate peaked at 10 percent in October 2009. Today, that rate hovers at about 4 percent. 19
Maintaining low unemployment levels is of concern not just to the United States but also to countries around the world. For example, high youth unemployment rates (for workers 25 years of age and younger) in Spain, Italy, and Greece continue to cause protests in these European countries as elected officials struggle with how to turn around their respective economies and put more people, particularly young people, back to work. The UK’s impending exit from the European Union may also have an effect on unemployment rates, as global companies move jobs out of Britain to central European countries such as Poland. 20
Measuring Unemployment
To determine how close we are to full employment, the government measures the unemployment rate . This rate indicates the percentage of the total labor force that is not working but is actively looking for work. It excludes “discouraged workers,” those not seeking jobs because they think no one will hire them. Each month the U.S. Department of Labor releases statistics on employment. These figures help us understand how well the economy is doing.
Types of Unemployment
Economists classify unemployment into four types: frictional, structural, cyclical, and seasonal. The categories are of small consolation to someone who is unemployed, but they help economists understand the problem of unemployment in our economy.
- Frictional unemployment is short-term unemployment that is not related to the business cycle. It includes people who are unemployed while waiting to start a better job, those who are reentering the job market, and those entering for the first time, such as new college graduates. This type of unemployment is always present and has little impact on the economy.
- Structural unemployment is also unrelated to the business cycle but is involuntary. It is caused by a mismatch between available jobs and the skills of available workers in an industry or a region. For example, if the birthrate declines, fewer teachers will be needed. Or the available workers in an area may lack the skills that employers want. Retraining and skill-building programs are often required to reduce structural unemployment.
- Cyclical unemployment , as the name implies, occurs when a downturn in the business cycle reduces the demand for labor throughout the economy. In a long recession, cyclical unemployment is widespread, and even people with good job skills can’t find jobs. The government can partly counteract cyclical unemployment with programs that boost the economy.
In the past, cyclical unemployment affected mainly less-skilled workers and those in heavy manufacturing. Typically, they would be rehired when economic growth increased. Since the 1990s, however, competition has forced many American companies to downsize so they can survive in the global marketplace. These job reductions affected workers in all categories, including middle management and other salaried positions. Firms continue to reevaluate workforce requirements and downsize to stay competitive to compete with Asian, European, and other U.S. firms. After a strong rebound from the global recession of 2007–2009, when the auto industry slashed more than 200,000 hourly and salaried workers from their payrolls, the automakers are now taking another close look at the size of their global workforces. For example, as sales steadily rose after the recession, Ford Motor Company’s workforce in North America increased by 25 percent over the past five years. As car sales plateaued in 2017, the company recently announced it would cut approximately 10 percent of its global workforce in an effort to reduce costs, boost profits, and increase its stock value for shareholders. 21
The last type is seasonal unemployment , which occurs during specific times of the year in certain industries. Employees subject to seasonal unemployment include retail workers hired for the holiday shopping season, lettuce pickers in California, and restaurant employees in ski country during the summer.
Keeping Prices Steady
The third macroeconomic goal is to keep overall prices for goods and services fairly steady. The situation in which the average of all prices of goods and services is rising is called inflation . Inflation’s higher prices reduce purchasing power , the value of what money can buy. Purchasing power is a function of two things: inflation and income. If incomes rise at the same rate as inflation, there is no change in purchasing power. If prices go up but income doesn’t rise or rises at a slower rate, a given amount of income buys less, and purchasing power falls. For example, if the price of a basket of groceries rises from $30 to $40 but your salary remains the same, you can buy only 75 percent as many groceries ($30 ÷ $40) for $30. Your purchasing power declines by 25 percent ($10 ÷ $40). If incomes rise at a rate faster than inflation, then purchasing power increases. So you can, in fact, have rising purchasing power even if inflation is increasing. Typically, however, inflation rises faster than incomes, leading to a decrease in purchasing power.
Inflation affects both personal and business decisions. When prices are rising, people tend to spend more—before their purchasing power declines further. Businesses that expect inflation often increase their supplies, and people often speed up planned purchases of cars and major appliances.
From the early 2000s to April 2017, inflation in the United States was very low, in the 0.1 to 3.8 percent range; for 2016 it was 1.3 percent. For comparison, in the 1980s, the United States had periods of inflation in the 12 to 13 percent range. 22 Some nations have had high double- and even triple-digit inflation in recent years. As of early 2017, the monthly inflation rate in Venezuela was an astounding 741 percent, followed by the African country of South Sudan at 273 percent. 23
Types of Inflation
There are two types of inflation. Demand-pull inflation occurs when the demand for goods and services is greater than the supply. Would-be buyers have more money to spend than the amount needed to buy available goods and services. Their demand, which exceeds the supply, tends to pull prices up. This situation is sometimes described as “too much money chasing too few goods.” The higher prices lead to greater supply, eventually creating a balance between demand and supply.
Cost-push inflation is triggered by increases in production costs, such as expenses for materials and wages. These increases push up the prices of final goods and services. Wage increases are a major cause of cost-push inflation, creating a “wage-price spiral.” For example, assume the United Auto Workers union negotiates a three-year labor agreement that raises wages 3 percent per year and increases overtime pay. Carmakers will then raise car prices to cover their higher labor costs. Also, the higher wages will give autoworkers more money to buy goods and services, and this increased demand may pull up other prices. Workers in other industries will demand higher wages to keep up with the increased prices, and the cycle will push prices even higher.
How Inflation Is Measured
The rate of inflation is most commonly measured by looking at changes in the consumer price index (CPI) , an index of the prices of a “market basket” of goods and services purchased by typical urban consumers. It is published monthly by the Department of Labor. Major components of the CPI, which are weighted by importance, are food and beverages, clothing, transportation, housing, medical care, recreation, and education. There are special indexes for food and energy. The Department of Labor collects about 80,000 retail price quotes and 5,000 housing rent figures to calculate the CPI.
The CPI sets prices in a base period at 100. The base period, which now is 1982–1984, is chosen for its price stability. Current prices are then expressed as a percentage of prices in the base period. A rise in the CPI means prices are increasing. For example, the CPI was 244.5 in April 2017, meaning that prices more than doubled since the 1982–1984 base period.
Changes in wholesale prices are another important indicator of inflation. The producer price index (PPI) measures the prices paid by producers and wholesalers for various commodities, such as raw materials, partially finished goods, and finished products. The PPI, which uses 1982 as its base year, is actually a family of indexes for many different product categories, including crude goods (raw materials), intermediate goods (which become part of finished goods), and finished goods. For example, the PPI for finished goods was 197.7 in April 2017, a 3.9-point increase, and for chemicals was 106.5, up 3.8 points since April 2016. Examples of other PPI indexes include processed foods, lumber, containers, fuels and lubricants, metals, and construction. Because the PPI measures prices paid by producers for raw materials, energy, and other commodities, it may foreshadow subsequent price changes for businesses and consumers.
The Impact of Inflation
Inflation has several negative effects on people and businesses. For one thing, inflation penalizes people who live on fixed incomes. Let’s say that a couple receives $2,000 a month retirement income beginning in 2018. If inflation is 10 percent in 2019, then the couple can buy only about 91 percent (100 ÷ 110) of what they could purchase in 2018. Similarly, inflation hurts savers. As prices rise, the real value, or purchasing power, of a nest egg of savings deteriorates.
CONCEPT CHECK
- What is a business cycle? How do businesses adapt to periods of contraction and expansion?
- Why is full employment usually defined as a target percentage below 100 percent?
- What is the difference between demand-pull and cost-push inflation?


7: Common Circuit Characteristics
Electrical components can be connected in different configurations to form circuits for different power outputs and applications.
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- 7.2: Parallel Circuits
- The parallel circuit is probably the most common type of circuit you will encounter. Loads in power distribution systems are usually connected in parallel with each other in one way or another. A parallel circuit is constructed by connecting the terminals of all the individual load devices so that the same value of voltage appears across each component.
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- 7.3: Voltage Source Circuits
- Multiple power sources can be connected in series or parallel in order to meet the different voltage or current output requirements for various applications: (1) Power sources are connected in series to increase the voltage output and (2) Power sources are connected in parallel to increase the current capacity


3.8: The Third Law of Thermodynamics
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In Section 21.7 , we obtain the entropy by a definite integration. We take the lower limits of integration, at \(T=0\), as \(P_1\left(0\right)=1\) and \(P_i\left(0\right)=0\), for \(i>1\). In doing so, we apply the third law of thermodynamics, which states that the entropy of a perfect crystal can be chosen to be zero when the temperature is at absolute zero. The idea behind the third law is that, at absolute zero, the molecules of a crystalline substance all are in the lowest energy level that is available to them. The probability that a molecule is in the lowest energy state is, therefore, \(P_1=1\), and the probability that it is any higher energy level, \(i>1\), is \(P_i=0\).
While the fact is not relevant to the present development, we note in passing that the energy of a perfect crystal is not zero at absolute zero. While all of the constituent particles will be in their lowest vibrational energy levels at absolute zero, the energies of these lowest vibrational levels are not zero. In the harmonic oscillator approximation, the lowest energy possible for each oscillator is \({h\nu }/{2}\). (See Section 18.5 ).
By a perfect crystalline substance we mean one in which the lowest energy level is non-degenerate; that is, for which \(g_1=1\). We see that our entropy equation conforms to the third law when we let
\[S_0=Nk \ln g_1 \nonumber \]
so that \(S_0=0\) when \(g_1=1\).
Let us consider a crystalline substance in which the lowest energy level is degenerate; that is, one for which \(g_1>1\). This substance is not a perfect crystal. In this case, the temperature-zero entropy is
\[S_0=Nk \ln g_1 >0 \nonumber \]
The question arises: How can we determine whether a crystalline substance is a perfect crystal? In Chapter 11 , we discuss the use of the third law to determine the absolute entropy of substances at ordinary temperatures. If we assume that the substance is a perfect crystal at zero degrees when it is not, our theory predicts a value for the absolute entropy at higher temperatures that is too small, because it does not include the term \(S_0=Nk\ln g_1\). When we use this too-small absolute entropy value to calculate entropy changes for processes involving the substance, the results do not agree with experiment.
Absolute entropies based on the third law have been experimentally determined for many substances. As a rule, the resulting entropies are consistent with other experimentally observed entropy changes. In some cases, however, the assumption that the entropy is zero at absolute zero leads to absolute entropy values that are not consistent with other experiments. In these cases, the absolute entropies can be brought into agreement with other entropy measurements by assuming that, indeed, \(g_1>1\) for such substances. In any particular case, the value of \(g_1\) that must be used is readily reconciled with other information about the substance.
For example, the third law entropy for carbon monoxide must be calculated taking \(g_1=2\) in order to obtain a value that is consistent with other entropy measurements. This observation is readily rationalized. In perfectly crystalline carbon monoxide, all of the carbon monoxide molecules point in the same direction, as sketched in Figure 11-2. However, the two ends of the carbon monoxide molecule are very similar, with the consequence that the carbon monoxide molecules in the crystal point randomly in either of two directions. Thus there are two (approximately) equally energetic states for a carbon monoxide molecule in a carbon monoxide crystal at absolute zero, and we can take \(g_1=2\). (We are over-simplifying here. We explore this issue further in Section 22-7 .)


10.2: Mindfulness Practice
First Skill to Learn, Last Skill to Perfect
Let’s do our last timed recording to compare our awesome improvement! We’ll use the same familiar phrase below since it incorporates all letters of the alphabet:
The Quick Brown Fox Jumps Over the Lazy Dog.
Set a timer for one minute and sign the above sentence as clearly and concisely as possible during that one-minute window. Remember our rules, however.
1) If you make an error, go back to the word (not the whole sentence) and fingerspell that word again and keep going.
2) Assign each word in the sentence a number so you can be exact in your end calculation. For example:
The = 1
Quick = 2
Brown = 3
Fox = 4
Jumps = 5
Over = 6
The = 7
Lazy = 8
Dog = 9
If my timer goes off, and I completed one full sentence and was on “fox”, I give myself a score of 1.4. If I’m faster than that, and I get three full sentences fingerspelled, but when the timer went off, I was signing “over”, I get a 3.6. Does this make sense?
3) Whatever word you’re on when the timer goes off, give yourself the full word.
4) Fingerspell the 1-minute recordings two times and record highest score below.
Ready, set, begin! Date____________________ High Score___________________________
Page 21 Date____________________ High Score___________________________
Page 5 Date____________________ High Score___________________________


12.3: Dijkstra's Algorithm for Shortest Paths
Just as with graphs, it is useful to assign weights to the directed edges of a digraph. Specifically, in this section we consider a pair \((\textbf{G},w)\) where \(\textbf{G}=(V,E)\) is a digraph and \(w:E \rightarrow \mathbb{N}_0\) is a function assigning to each directed edge \((x,y)\) a non-negative weight \(w(x,y)\). However, in this section, we interpret weight as distance so that \(w(x,y)\) is now called the length of the edge \((x,y)\). If \(P=(r=u_0,u_1,…,u_t=x)\) is a directed path from \(r\) to \(x\), then the length of the path \(P\) is just the sum of the lengths of the edges in the path, \(\sum_{i=0}^{t-1} w(u_iu_{i+1})\). The distance from \(r\) to \(x\) is then defined to be the minimum length of a directed path from \(r\) to \(x\). Our goal in this section is to solve the following natural problem, which has many applications:
For each vertex \(x\), find the distance from \(r\) to \(x\). Also, find a shortest path from \(r\) to \(x\).
12.3.1 Description of the Algorithm
To describe Dijkstra's algorithm in a compact manner, it is useful to extend the definition of the function \(w\). We do this by setting \(w(x,y)= \infty\) when \(x \neq y\) and \((x,y)\) is not a directed edge of \(\textbf{G}\). In this way, we will treat \(\infty\) as if it were a number (although it is not!).
We are now prepared to describe Dijkstra's Algorithm.
Let \(n=|V|\) . At Step \(i\) , where \(1≤i≤n\) , we will have determined:
- A sequence \(σ=(v_1,v_2,v3,…,v_i)\) of distinct vertices from \(\textbf{G}\) with \(r=v_1\) . These vertices are called permanent vertices , while the remaining vertices will be called temporary vertices .
- For each vertex \(x∈V\) , we will have determined a number \(δ(x)\) and a path \(P(x)\) from \(r\) to \(x\) of length \(δ(x)\) .
Initialization (Step 1)
Set \(i=1\) . Set \(δ(r)=0\) and let \(P(r)=(r)\) be the trivial one-point path. Also, set \(σ=(r)\) . For each \(x≠r\) , set \(δ(x)=w(r,x)\) and \(P(x)=(r,x)\) . Let \(x\) be a temporary vertex for which \(δ(x)\) is minimum. Set \(v_2=x\) , and update \(σ\) by appending \(v_2\) to the end of it. Increment \(i\) .
Inductive Step (Step \(i, i > 1\) )
If \(i<n\) , then for each temporary \(x\), let
\(δ(x)=min\{δ(x),δ(v_i)+w(v_i,x)\}\).
If this assignment results in a reduction in the value of \(δ(x)\) , let \(P(x)\) be the path obtained by adding \(x\) to the end of \(P(v_i)\) .
Let \(x\) be a temporary vertex for which \(δ(x)\) is minimum. Set \(v_{i+1}=x\) , and update \(σ\) by appending \(v_{i+1}\) to it. Increment \(i\) .
12.3.2 Example of Dijkstra's Algorithm
Before establishing why Dijkstra's algorithm works, it may be helpful to see an example of how it works. To do this, consider the digraph \(\textbf{G}\) shown in Figure 12.15 . For visual clarity, we have chosen a digraph which is an oriented graph , i.e., for each distinct pair \(x,y\) of vertices, the graph contains at most one of the two possible directed edges \((x,y)\) and \((y,x)\).
Suppose that the root vertex \(r\) is the vertex labeled \(a\). The initialization step of Dijkstra's algorithm then results in the following values for \(δ\) and \(P\):
Step 1. Initialization.
\(σ=(a)\)
\(δ(a)=0;P(a)=(a)\)
\(δ(b)= \infty ;P(b)=(a,b)\)
\(δ(c)=47;P(c)=(a,c)\)
\(δ(d)= \infty ;P(d)=(a,d)\)
\(δ(e)=70;P(e)=(a,e)\)
\(δ(f)=24;P(f)=(a,f)\)
\(δ(g)= \infty ;P(g)=(a,g)\)
\(δ(h)= \infty ;P(h)=(a,h)\)
Before finishing Step 1, the algorithm identifies vertex \(f\) as closest to \(a\) and appends it to \(σ\), making \(a\) permanent. When entering Step 2, Dijkstra's algorithm attempts to find shorter paths from \(a\) to each of the temporary vertices by going through \(f\). We call this process “scanning from vertex \(f\).” In this scan, the path to vertex \(d\) is updated, since \(δ(f) + w(f,d) = 24 + 120 = 144 < \infty = w(a,d)\).
Step 2. Scan from vertex \(f\) .
\(σ=(a,f)\)
\(δ(a)=0;P(a)=(a)\)
\(δ(b)= \infty;P(b)=(a,b)\)
\(δ(c)=47;P(c)=(a,c)\)
\(δ(d)=144=24+120=δ(f)+w(f,d);P(d)=(a,f,d)\) updated
\(δ(e)=70;P(e)=(a,e)\)
\(δ(f)=24;P(f)=(a,f)\)
\(δ(g)= \infty ;P(g)=(a,f)\)
\(δ(h)= \infty ;P(h)=(a,h)\)
Before proceeding to the next step, vertex \(c\) is made permanent by making it \(v_3\). In Step 3, therefore, the scan is from vertex \(c\). Vertices \(b, d\), and \(g\) have their paths updated. However, although \(δ(c)+w(c,e)=47+23=70=δ(e)\), we do not change \(P(e)\) since \(δ(e)\) is not decreased by routing \(P(e)\) through \(c\).
Step 3. Scan from vertex \(c\) .
\(σ=(a,f,c)\)
\(δ(a)=0;P(a)=(a)\)
\(δ(b)=102=47+55=δ(c)+w(c,b);P(b)=(a,c,b)\) updated
\(δ(c)=47;P(c)=(a,c)\)
\(δ(d)=135=47+88=δ(c)+w(c,d);P(d)=(a,c,d)\) updated
\(δ(e)=70;P(e)=(a,e)\)
\(δ(f)=24;P(f)=(a,f)\)
\(δ(g)=113=47+66=δ(c)+w(c,g);P(g)=(a,c,g)\) updated
\(δ(h)= \infty;P(h)=(a,h)\)
Now vertex \(e\) is made permanent.
Step 4. Scan from vertex e.
\(σ=(a,f,c,e)\)
\(δ(a)=0;P(a)=(a)\)
\(δ(b)=101=70+31=δ(e)+w(e,b);P(b)=(a,e,b)\) updated
\(δ(c)=47;P(c)=(a,c)\)
\(δ(d)=135;P(d)=(a,c,d)\)
\(δ(e)=70;P(e)=(a,e)\)
\(δ(f)=24;P(f)=(a,f)\)
\(δ(g)=112=70+42=δ(e)+w(e,g);P(g)=(a,e,g)\) updated
\(δ(h)= \infty;P(h)=(a,h)\)
Now vertex \(b\) is made permanent.
Step 5. Scan from vertex b.
\(σ=(a,f,c,e,b)\)
\(δ(a)=0;P(a)=(a)\)
\(δ(b)=101;P(b)=(a,e,b)\)
\(δ(c)=47;P(c)=(a,c)\)
\(δ(d)=132=101+31=δ(b)+w(b,d);P(d)=(a,e,b,d)\) updated
\(δ(e)=70;P(e)=(a,e)\)
\(δ(f)=24;P(f)=(a,f)\)
\(δ(g)=112;P(g)=(a,e,g)\)
\(δ(h)=180=101+79=δ(b)+w(b,h);P(h)=(a,e,b,h)\) updated
Now vertex \(g\) is made permanent.
Step 6. Scan from vertex g.
\(σ=(a,f,c,e,b,g)\)
\(δ(a)=0;P(a)=(a)\)
\(δ(b)=101;P(b)=(a,e,b)\)
\(δ(c)=47;P(c)=(a,c)\)
\(δ(d)=132;P(d)=(a,e,b,d)\)
\(δ(e)=70;P(e)=(a,e)\)
\(δ(f)=24;P(f)=(a,f)\)
\(δ(g)=112;P(g)=(a,e,g)\)
\(δ(h)=178=112+66=δ(g)+w(g,h);P(h)=(a,e,g,h)\) updated
Now vertex \(d\) is made permanent.Step 7. Scan from vertex d.
\(σ=(a,f,c,e,b,g,d)\)
\(δ(a)=0;P(a)=(a)\)
\(δ(b)=101;P(b)=(a,e,b)\)
\(δ(c)=47;P(c)=(a,c)\)
\(δ(d)=132;P(d)=(a,e,b,d)\)
\(δ(e)=70;P(e)=(a,e)\)
\(δ(f)=24;P(f)=(a,f)\)
\(δ(g)=112;P(g)=(a,e,g)\)
\(δ(h)=161=132+29=δ(d)+w(d,h);P(h)=(a,e,b,d,h)\) updated
Now vertex \(h\) is made permanent. Since this is the last vertex, the algorithm halts and returns the following:
Final Results of Dijkstra's Algorithm.
\(σ=(a,f,c,e,b,g,d,h)\)
\(δ(a)=0;P(a)=(a)\)
\(δ(b)=101;P(b)=(a,e,b)\)
\(δ(c)=47;P(c)=(a,c)\)
\(δ(d)=132;P(d)=(a,e,b,d)\)
\(δ(e)=70;P(e)=(a,e)\)
\(δ(f)=24;P(f)=(a,f)\)
\(δ(g)=112;P(g)=(a,e,g)\)
\(δ(h)=161;P(h)=(a,e,b,d,h)\)
12.3.3 The Correctness of Dijkstra's Algorithm
Now that we've illustrated Dijkstra's algorithm, it's time to prove that it actually does what we claimed it does: find the distance from the root vertex to each of the other vertices and a path of that length. To do this, we first state two elementary propositions. The first is about shortest paths in general, while the second is specific to the sequence of permanent vertices produced by Dijkstra's algorithm.
Let \(x\) be a vertex and let \(P=(r=u_0,u_1,…,u_t=x)\) be a shortest path from \(r\) to \(x\) . Then for every integer \(j\) with \(0<j<t\), \((u_0,u_1,…,u_j)\) is a shortest path from \(r\) to \(u_j\) and \((u_j,u_{j+1},…,u_t)\) is a shortest path from \(u_j\) to \(u_t\)
When the algorithm halts, let \(σ=(v_1,v_2,v_3,…,v_n)\) . Then
\(δ(v_1) \leq δ(v_2) \leq \cdot \cdot \cdot \leq δ(v_n)\).
We are now ready to prove the correctness of the algorithm. The proof we give will be inductive, but the induction will have nothing to do with the total number of vertices in the digraph or the step number the algorithm is in.
Dijkstra's algorithm yields shortest paths for every vertex \(x\) in \(\textbf{G}\) . That is, when Dijkstra's algorithm terminates, for each \(x \in V\) , the value \(δ(x)\) is the distance from \(r\) to \(x\) and \(P(x)\) is a shortest path from \(r\) to \(x\) .
- Proof
-
The theorem holds trivially when \(x=r\). So we consider the case where \(x \neq r\). We argue that \(δ(x)\) is the distance from \(r\) to \(x\) and that \(P(x)\) is a shortest path from \(r\) to \(x\) by induction on the minimum number \(k\) of edges in a shortest path from \(r\) to \(x\). When \(k=1\), the edge \((r,x)\) is a shortest path from \(r\) to \(x\). Since \(v_1=r\), we will set \(δ(x)=w(r,x)\) and \(P(x)=(r,x)\) at Step 1.
Now fix a positive integer \(k\). Assume that if the minimum number of edges in a shortest path from \(r\) to \(x\) is at most \(k\), then \(δ(x)\) is the distance from \(r\) to \(x\) and \(P(x)\) is a shortest path from \(r\) to \(x\). Let \(x\) be a vertex for which the minimum number of edges in a shortest path from \(r\) to \(x\) is \(k+1\). Fix a shortest path \(P=(u_0,u_1,u_2,…,u_{k+1})\) from \(r=u_0\) to \(x=u_{k+1}\). Then \(Q=(u_0,u_1,…,u_k)\) is a shortest path from \(r\) to \(u_k\). (See Figure 12.19 .)
By the inductive hypothesis, \(δ(u_k)\) is the distance from \(r\) to \(u_k\), and \(P(u_k)\) is a shortest path from \(r\) to \(u_k\). Note that \(P(u_k)\) need not be the same as path \(Q\), as we suggest in Figure 12.19 . However, if distinct, the two paths will have the same length, namely \(δ(u_k)\). Also, the distance from \(r\) to \(x\) is \(δ(u_k)+w(u_k,x) \geq δ(u_k)\) since \(P\) is a shortest path from \(r\) to \(x\) and \(w(u_k,x)≥0\).
Let \(i\) and \(j\) be the unique integers for which \(u_k=v_i\) and \(x=v_j\). If \(j<i\), then
\(δ(x)=δ(v_j)≤δ(v_i)=δ(u_k)≤δ(u_k)+w(u_k)\).
Therefore the algorithm has found a path \(P(x)\) from \(r\) to \(x\) having length \(δ(x)\) which is at most the distance from \(r\) to \(x\). Clearly, this implies that \(δ(x)\) is the distance from \(r\) to \(x\) and that \(P(x)\) is a shortest path.
On the other hand, if \(j>i\), then the inductive step at Step \(i\) results in
\(δ(x)≤δ(v_i)+w(v_i,y)=δ(u_k)+w(u_k,x)\).
As before, this implies that \(δ(x)\) is the distance from \(r\) to \(x\) and that \(P(x)\) is a shortest path.


8.7: Tips for Writing Academic Persuasive Essays
The previous chapters in this section offer an overview of what it means to formulate an argument in an academic situation. The purpose of this chapter is to offer more concrete, actionable tips for drafting an academic persuasive essay. Keep in mind that preparing to draft a persuasive essay relies on the strategies for any other thesis-driven essay, covered by the section in this textbook, The Writing Process. The following chapters can be read in concert with this one:
- Critical Reading and other research strategies helps writers identify the exigence (issue) that demands a response, as well as what kinds of research to use.
- Generate Ideas covers prewriting models (such as brainstorming techniques) that allow students to make interesting connections and develop comprehensive thesis statements. These connections and main points will allow a writer to outline their core argument.
- Organizing is important for understanding why an argument essay needs a detailed plan, before the drafting stage. For an argument essay, start with a basic outline that identifies the claim, reasoning, and evidence, but be prepared to develop more detailed outlines that include counterarguments and rebuttals, warrants, additional backing, etc., as needed.
- Drafting introduces students to basic compositional strategies that they must be familiar with before beginning an argument essay. This current chapter offers more details about what kinds of paragraphs to practice in an argument essay, but it assumes the writer is familiar with basic strategies such as coherence and cohesion.
Classical structure of an argument essay
Academic persuasive essays tend to follow what’s known as the “classical” structure, based on techniques that derive from ancient Roman and Medieval rhetoricians. John D. Ramage, et. al outline this structure in Writing Arguments :
|
Introduction (one to several paragraphs) |
|
|
Presentation of writer’s position |
|
|
Summary of opposing views (Counterarguments)
Response to opposing views (Rebuttals) |
|
|
Conclusion |
|
This very detailed table can be simplified. Most academic persuasive essays include the following basic elements:
- Introduction that explains why the situation is important and presents your argument (aka the claim or thesis).
-
Support/Body
- Reasons the thesis is correct or at least reasonable.
- Evidence that supports each reason, often occurring right after the reason the evidence supports.
- Acknowledgement of objections.
- Response to objections.
- Conclusion
Keep in mind that the structure above is just a conventional starting point. The previous chapters of this section suggest how different kinds of arguments (Classical/Aristotelian, Toulmin, Rogerian) involve slightly different approaches, and your course, instructor, and specific assignment prompt may include its own specific instructions on how to complete the assignment. There are many different variations. At the same time, however, most academic argumentative/persuasive essays expect you to practice the techniques mentioned below. These tips overlap with the elements of argumentation, covered in that chapter, but they offer more explicit examples for how they might look in paragraph form, beginning with the introduction to your essay.
Persuasive introductions should move from context to thesis
Since one of the main goals of a persuasive essay introduction is to forecast the broader argument, it’s important to keep in mind that the legibility of the argument depends on the ability of the writer to provide sufficient information to the reader. If a basic high school essay moves from general topic to specific argument (the funnel technique), a more sophisticated academic persuasive essay is more likely to move from context to thesis.
The great stylist of clear writing, Joseph W. Williams, suggests that one of the key rhetorical moves a writer can make in a persuasive introduction is to not only provide enough background information (the context), but to frame that information in terms of a problem or issue, what the section on Reading and Writing Rhetorically terms the exigence . The ability to present a clearly defined problem and then the thesis as a solution creates a motivating introduction. The reader is more likely to be gripped by it, because we naturally want to see problems solved.
Consider these two persuasive introductions, both of which end with an argumentative thesis statement:
A. In America we often hold to the belief that our country is steadily progressing. topic This is a place where dreams come true. With enough hard work, we tell ourselves (and our children), we can do anything. I argue that, when progress is more carefully defined, our current period is actually one of decline. claim
B . Two years ago my dad developed Type 2 diabetes, and the doctors explained to him that it was due in large part to his heavy consumption of sugar. For him, the primary form of sugar consumption was soda. hook His experience is echoed by millions of Americans today. According to the most recent research, “Sugary drink portion sizes have risen dramatically over the past forty years, and children and adults are drinking more soft drinks than ever,” while two out of three adults in the United States are now considered either overweight or obese. This statistic correlates with reduced life expectancy by many years. Studies have shown that those who are overweight in this generation will live a lot fewer years than those who are already elderly. And those consumers who don’t become overweight remain at risk for developing Type 2 diabetes (like my dad), known as one of the most serious global health concerns (“Sugary Drinks and Obesity Fact Sheet”). problem In response to this problem, some political journalists, such as Alexandra Le Tellier, argue that sodas should be banned. On the opposite end of the political spectrum, politically conservative journalists such as Ernest Istook argue that absolutely nothing should be done because that would interfere with consumer freedom. debate I suggest something in between: a “soda tax,” which would balance concerns over the public welfare with concerns over consumer freedom. claim
Example B feels richer, more dramatic, and much more targeted not only because it’s longer, but because it’s structured in a “motivating” way. Here’s an outline of that structure:
- Hook: It opens with a brief hook that illustrates an emerging issue. This concrete, personal anecdote grips the reader’s attention.
-
Context (background information)
- Problem: The anecdote is connected with the emerging issue, phrased as a problem that needs to be addressed.
- Debate: The writer briefly alludes to a debate over how to respond to the problem.
- Claim: The introduction ends by hinting at how the writer intends to address the problem, and it’s phrased conversationally, as part of an ongoing dialogue.
Not every persuasive introduction needs all of these elements. Not all introductions will have an obvious problem. Sometimes a “problem,” or the exigence, will be as subtle as an ambiguity in a text that needs to be cleared up (as in literary analysis essays). Other times it will indeed be an obvious problem, such as in a problem-solution argument essay.
In most cases, however, a clear introduction will proceed from context to thesis . The most attention-grabbing and motivating introductions will also include things like hooks and problem-oriented issues.
Here’s a very simple and streamlined template that can serve as rudimentary scaffolding for a persuasive introduction, inspired by the excellent book, They Say / I Say: The Moves That Matter in Academic Writing :
In discussions of __________, an emerging issue is _____________________. issue When addressing this issue, some experts suggest ________________. debate In my view, however, _______________________________. claim
Each aspect of the template will need to be developed, but it can serve as training wheels for how to craft a nicely structured context-to-thesis introduction, including things like an issue, debate, and claim. You can try filling in the blanks below, and then export your attempt as a document.
Define key terms, as needed
Much of an academic persuasive essay is dedicated to supporting the claim. A traditional thesis-driven essay has an introduction, body, and conclusion, and the support constitutes much of the body. In a persuasive essay, most of the support is dedicated to reasoning and evidence (more on that below). However, depending on what your claim does, a careful writer may dedicate the beginning (or other parts of the essay body) to defining key terms.
Suppose I wish to construct an argument that enters the debate over euthanasia. When researching the issue, I notice that much of the debate circles around the notion of rights, specifically what a “legal right” actually means. Clearly defining that term will help reduce some of the confusion and clarify my own argument. In Vancouver Island University’s resource “ Defining key terms ,” Ian Johnston offers this example for how to define “legal right” for an academic reader:
Before discussing the notion of a right to die, we need to clarify precisely what the term legal right means. In common language, the term “right” tends often to mean something good, something people ought to have (e.g., a right to a good home, a right to a meaningful job, and so on). In law, however, the term has a much more specific meaning. It refers to something to which people are legally entitled. Thus, a “legal” right also confers a legal obligation on someone or some institution to make sure the right is conferred. For instance, in Canada, children of a certain age have a right to a free public education. This right confers on society the obligation to provide that education, and society cannot refuse without breaking the law. Hence, when we use the term right to die in a legal sense, we are describing something to which a citizen is legally entitled, and we are insisting that someone in society has an obligation to provide the services which will confer that right on anyone who wants it.
As the example above shows, academics often dedicate space to providing nuanced and technical definitions that correct common misconceptions. Johnston’s definition relies on research, but it’s not always necessary to use research to define your terms. Here are some tips for crafting definitions in persuasive essays, from “Defining key terms”:
- Fit the descriptive detail in the definition to the knowledge of the intended audience. The definition of, say, AIDS for a general readership will be different from the definition for a group of doctors (the latter will be much more technical). It often helps to distinguish between common sense or popular definitions and more technical ones.
- Make sure definitions are full and complete; do not rush them unduly. And do not assume that just because the term is quite common that everyone knows just what it means (e.g., alcoholism ). If you are using the term in a very specific sense, then let the reader know what that is. The amount of detail you include in a definition should cover what is essential for the reader to know, in order to follow the argument. By the same token, do not overload the definition, providing too much detail or using far too technical a language for those who will be reading the essay.
- It’s unhelpful to simply quote the google or dictionary.com definition of a word. Dictionaries contain a few or several definitions for important terms, and the correct definition is informed by the context in which it’s being employed. It’s up to the writer to explain that context and how the word is usually understood within it.
- You do not always need to research a definition. Depending on the writing situation and audience, you may be able to develop your own understanding of certain terms.
Use P-E-A-S or M-E-A-L to support your claim
The heart of a persuasive essay is a claim supported by reasoning and evidence. Thus, much of the essay body is often devoted to the supporting reasons, which in turn are proved by evidence. One of the formulas commonly taught in K-12 and even college writing programs is known as PEAS, which overlaps strongly with the MEAL formula introduced by the chapter, “ Basic Integration “:
Point : State the reasoning as a single point: “One reason why a soda tax would be effective is that…” or “One way an individual can control their happiness is by…”
Evidence : After stating the supporting reason, prove that reason with related evidence. There can be more than one piece of evidence. “According to …” or “In the article, ‘…,’ the author shows that …”
Analysis : There a different levels of analysis. At the most basic level, a writer should clearly explain how the evidence proves the point, in their own words: “In other words…,” “What this data shows is that…” Sometimes the “A” part of PEAS becomes simple paraphrasing. Higher-level analysis will use more sophisticated techniques such as Toulmin’s warrants to explore deeper terrain. For more tips on how to discuss and analyze, refer to the previous chapter’s section, “ Analyze and discuss the evidence .”
Summary/So what? : Tie together all of the components (PEA) succinctly, before transitioning to the next idea. If necessary, remind the reader how the evidence and reasoning relates to the broader claim (the thesis argument).
PEAS and MEAL are very similar; in fact they are identical except for how they refer to the first and last part. In theory, it shouldn’t matter which acronym you choose. Both versions are effective because they translate the basic structure of a supporting reason (reasoning and evidence) into paragraph form.
Here’s an example of a PEAS paragraph in an academic persuasive essay that argues for a soda tax:
A soda tax would also provide more revenue for the federal government, thereby reducing its debt. point Despite Ernest Istook’s concerns about eroding American freedom, the United States has long supported the ability of government to leverage taxes in order to both curb unhealthy lifestyles and add revenue. According to Peter Ubel’s “Would the Founding Fathers Approve of a Sugar Tax?”, in 1791 the US government was heavily in debt and needed stable revenue. In response, the federal government taxed what most people viewed as a “sin” at that time: alcohol. This single tax increased government revenue by at least 20% on average, and in some years more than 40% . The effect was that only the people who really wanted alcohol purchased it, and those who could no longer afford it were getting rid of what they already viewed as a bad habit (Ubel). evidence Just as alcohol (and later, cigarettes) was viewed as a superfluous “sin” in the Early Republic, so today do many health experts and an increasing amount of Americans view sugar as extremely unhealthy, even addictive. If our society accepts taxes on other consumer sins as a way to improve government revenue, a tax on sugar is entirely consistent. analysis We could apply this to the soda tax and try to do something like this to help knock out two problems at once: help people lose their addiction towards soda and help reduce our government’s debt. summary/so what?
The paragraph above was written by a student who was taught the PEAS formula. However, we can see versions of this formula in professional writing. Here’s a more sophisticated example of PEAS, this time from a non-academic article. In Nicholas Carr’s extremely popular article, “ Is Google Making Us Stupid? “, he argues that Google is altering how we think. To prove that broader claim, Carr offers a variety of reasons and evidence. Here’s part of his reasoning:
Thanks to the ubiquity of text on the Internet, not to mention the popularity of text-messaging on cell phones, we may well be reading more today than we did in the 1970s or 1980s, when television was our medium of choice. But it’s a different kind of reading, and behind it lies a different kind of thinking—perhaps even a new sense of the self. point “We are not only what we read,” says Maryanne Wolf, a developmental psychologist at Tufts University and the author of Proust and the Squid: The Story and Science of the Reading Brain . “We are how we read.” Wolf worries that the style of reading promoted by the Net, a style that puts “efficiency” and “immediacy” above all else, may be weakening our capacity for the kind of deep reading that emerged when an earlier technology, the printing press, made long and complex works of prose commonplace. When we read online, she says, we tend to become “mere decoders of information.” evidence Our ability to interpret text, to make the rich mental connections that form when we read deeply and without distraction, remains largely disengaged. analysis
This excerpt only contains the first three elements, PEA, and the analysis part is very brief (it’s more like paraphrase), but it shows how professional writers often employ some version of the formula. It tends to appear in persuasive texts written by experienced writers because it reinforces writing techniques mentioned elsewhere in this textbook. A block of text structured according to PEA will practice coherence, because opening with a point (P) forecasts the main idea of that section. Embedding the evidence (E) within a topic sentence and follow-up commentary or analysis (A) is part of the “quote sandwich” strategy we cover in the section on “Writing With Sources.”
Use “they say / i say” strategies for Counterarguments and rebuttals
Another element that’s unique to persuasive essays is embedding a counterargument. Sometimes called naysayers or opposing positions, counterarguments are points of view that challenge our own.
Why embed a naysayer?
Recall above how a helpful strategy for beginning a persuasive essay (the introduction) is to briefly mention a debate—what some writing textbooks call “joining the conversation.” Gerald Graff and Cathy Birkenstein’s They Say / I Say explains why engaging other points of view is so crucial:
Not long ago we attended a talk at an academic conference where the speaker’s central claim seemed to be that a certain sociologist—call him Dr. X—had done very good work in a number of areas of the discipline. The speaker proceeded to illustrate his thesis by referring extensively and in great detail to various books and articles by Dr. X and by quoting long pas-sages from them. The speaker was obviously both learned and impassioned, but as we listened to his talk we found ourselves somewhat puzzled: the argument—that Dr. X’s work was very important—was clear enough, but why did the speaker need to make it in the first place? Did anyone dispute it? Were there commentators in the field who had argued against X’s work or challenged its value? Was the speaker’s interpretation of what X had done somehow novel or revolutionary? Since the speaker gave no hint of an answer to any of these questions, we could only wonder why he was going on and on about X. It was only after the speaker finished and took questions from the audience that we got a clue: in response to one questioner, he referred to several critics who had vigorously questioned Dr. X’s ideas and convinced many sociologists that Dr. X’s work was unsound.
When writing for an academic audience, one of the most important moves a writer can make is to demonstrate how their ideas compare to others. It serves as part of the context. Your essay might be offering a highly original solution to a certain problem you’ve researched the entire semester, but the reader will only understand that if existing arguments are presented in your draft. Or, on the other hand, you might be synthesizing or connecting a variety of opinions in order to arrive at a more comprehensive solution. That’s also fine, but the creativity of your synthesis and its unique contribution to existing research will only be known if those other voices are included.
Aristotelian argumentation embeds counterarguments in order to refute them. Rogerian arguments present oppositional stances in order to synthesize and integrate them. No matter what your strategy is, the essay should be conversational.
Notice how Ana Mari Cauce opens her essay on free speech in higher education, “ Messy but Essential “:
Over the past year or two, issues surrounding the exercise of free speech and expression have come to the forefront at colleges around the country. The common narrative about free speech issues that we so often read goes something like this: today’s college students — overprotected and coddled by parents, poorly educated in high school and exposed to primarily left-leaning faculty — have become soft “snowflakes” who are easily offended by mere words and the slightest of insults, unable or unwilling to tolerate opinions that veer away from some politically correct orthodoxy and unable to engage in hard-hitting debate. counterargument
This is false in so many ways, and even insulting when you consider the reality of students’ experiences today. claim
The introduction to her article is essentially a counteragument (which serves as her introductory context) followed by a response. Embedding naysayers like this can appear anywhere in an essay, not just the introduction. Notice, furthermore, how Cauce’s naysayer isn’t gleaned from any research she did. It’s just a general, trendy naysayer, something one might hear nowadays, in the ether. It shows she’s attuned to an ongoing conversation, but it doesn’t require her to cite anything specific. As the previous chapter on using rhetorical appeals in arguments explained, this kind of attunement with an emerging problem (or exigence) is known as the appeal to kairos . A compelling, engaging introduction will demonstrate that the argument “kairotically” addresses a pressing concern.
Below is a brief overview of what counterarguments are and how you might respond to them in your arguments. This section was developed by Robin Jeffrey, in “ Counterargument and Response “:
Common Types of counterarguments
- Could someone disagree with your claim? If so, why? Explain this opposing perspective in your own argument, and then respond to it.
- Could someone draw a different conclusion from any of the facts or examples you present? If so, what is that different conclusion? Explain this different conclusion and then respond to it.
- Could a reader question any of your assumptions or claims? If so, which ones would they question? Explain and then respond.
- Could a reader offer a different explanation of an issue? If so, what might their explanation be? Describe this different explanation, and then respond to it.
- Is there any evidence out there that could weaken your position? If so, what is it? Cite and discuss this evidence and then respond to it.
If the answer to any of these questions is yes, that does not necessarily mean that you have a weak argument. It means, ideally and as long as your argument is logical and valid, that you have a counterargument. Good arguments can and do have counterarguments; it is important to discuss them. But you must also discuss and then respond to those counterarguments.
Responding to counterarguments
You do not need to attempt to do all of these things as a way to respond; instead, choose the response strategy that makes the most sense to you, for the counterargument that you have.
- If you agree with some of the counterargument perspectives, you can concede some of their points. (“I do agree that ….”, “Some of the points made by ____ are valid…..”) You could then challenge the importance/usefulness of those points. “However, this information does not apply to our topic because…”
- If the counterargument perspective is one that contains different evidence than you have in your own argument, you can explain why a reader should not accept the evidence that the counterarguer presents.
- If the counterargument perspective is one that contains a different interpretation of evidence than you have in your own argument, you can explain why a reader should not accept the interpretation of the evidence that that your opponent (counterarguer) presents.
- If the counterargument is an acknowledgement of evidence that threatens to weaken your argument, you must explain why and how that evidence does not, in fact invalidate your claim.
It is important to use transitional phrases in your paper to alert readers when you’re about to present an counterargument. It’s usually best to put this phrase at the beginning of a paragraph such as:
- Researchers have challenged these claims with…
- Critics argue that this view…
- Some readers may point to…
- A perspective that challenges the idea that . . .
Transitional phrases will again be useful to highlight your shift from counterargument to response:
- Indeed, some of those points are valid. However, . . .
- While I agree that . . . , it is more important to consider . . .
- These are all compelling points. Still, other information suggests that . .
- While I understand . . . , I cannot accept the evidence because . . .
Further reading
To read more about the importance of counterarguments in academic writing, read Steven D. Krause’s “ On the Other Hand: The Role of Antithetical Writing in First Year Composition Courses .”
When concluding, address the “so what?” challenge
As Joseph W. Williams mentions in his chapter on concluding persuasive essays in Style ,
a good introduction motivates your readers to keep reading, introduces your key themes, and states your main point … [but] a good conclusion serves a different end: as the last thing your reader reads, it should bring together your point, its significance, and its implications for thinking further about the ideas your explored.
At the very least, a good persuasive conclusion will
- Summarize the main points
- Address the So what? or Now what? challenge.
When summarizing the main points of longer essays, Williams suggests it’s fine to use “metadiscourse,” such as, “I have argued that.” If the essay is short enough, however, such metadiscourses may not be necessary, since the reader will already have those ideas fresh in their mind.
After summarizing your essay’s main points, imagine a friendly reader thinking,
“OK, I’m persuaded and entertained by everything you’ve laid out in your essay. But remind me what’s so important about these ideas? What are the implications? What kind of impact do you expect your ideas to have? Do you expect something to change?”
It’s sometimes appropriate to offer brief action points, based on the implications of your essay. When addressing the “So what?” challenge, however, it’s important to first consider whether your essay is primarily targeted towards changing the way people think or act . Do you expect the audience to do something, based on what you’ve argued in your essay? Or, do you expect the audience to think differently? Traditional academic essays tend to propose changes in how the reader thinks more than acts, but your essay may do both.
Finally, Williams suggests that it’s sometimes appropriate to end a persuasive essay with an anecdote, illustrative fact, or key quote that emphasizes the significance of the argument. We can see a good example of this in Carr’s article, “ Is Google Making Us Stupid? ” Here are the introduction and conclusion, side-by-side:
[Introduction] “Dave, stop. Stop, will you? Stop, Dave. Will you stop, Dave?” So the supercomputer HAL pleads with the implacable astronaut Dave Bowman in a famous and weirdly poignant scene toward the end of Stanley Kubrick’s 2001: A Space Odyssey . Bowman, having nearly been sent to a deep-space death by the malfunctioning machine, is calmly, coldly disconnecting the memory circuits that control its artificial “ brain. “Dave, my mind is going,” HAL says, forlornly. “I can feel it. I can feel it.”
I can feel it, too. Over the past few years I’ve had an uncomfortable sense that someone, or something, has been tinkering with my brain, remapping the neural circuitry, reprogramming the memory. …
[Conclusion] I’m haunted by that scene in 2001 . What makes it so poignant, and so weird, is the computer’s emotional response to the disassembly of its mind: its despair as one circuit after another goes dark, its childlike pleading with the astronaut—“I can feel it. I can feel it. I’m afraid”—and its final reversion to what can only be called a state of innocence. HAL’s outpouring of feeling contrasts with the emotionlessness that characterizes the human figures in the film, who go about their business with an almost robotic efficiency. Their thoughts and actions feel scripted, as if they’re following the steps of an algorithm. In the world of 2001 , people have become so machinelike that the most human character turns out to be a machine. That’s the essence of Kubrick’s dark prophecy: as we come to rely on computers to mediate our understanding of the world, it is our own intelligence that flattens into artificial intelligence.
Instead of merely rehashing all of the article’s main points, Carr returns to the same movie scene from 2001 that he opened with. The final lines interpret the scene according to the argument he just dedicated the entire essay to presenting.
The entire essay should use rhetorical appeals strategically
The chapter “ Persuasive Appeals ” introduces students to logos, pathos, ethos, and kairos. Becoming familiar with each of those persuasive appeals can add much to an essay. It also reinforces the idea that writing argumentative essays is not a straightforward process of jotting down proofs. It’s not a computer algorithm.
- Logos (appeals to evidence and reasoning) is the foundational appeal of an argument essay. Clearly identifying the claim, then supporting that claim with reasoning and evidence will appeal to the reader’s logos demands. As the previous chapter on argumentation mentions, however, what constitutes solid evidence will vary depending on the audience. Make sure your evidence is indeed convincing to your intended reader.
- Pathos (appeals to emotion) are a crucial component and should permeate should every section of the essay. Personal anecdotes are an effective way to illustrate important ideas, and they connect with the reader at an emotional level. Personal examples also cultivate voice .
- Ethos (appeals to character, image, and values) is essential to gaining the reader’s trust and assent. The tone of your essay (snarky, sincere, ironic, sarcastic, empathetic) is immensely important for its overall effect, and it helps build the reader’s image of you. A careful attention to high-quality research reinforces a sincere and empathetic tone. When supporting certain claims and sub-claims, it’s also important to identify implied beliefs (warrants) that your reader is most likely to agree with, and to undermine beliefs that might seem repugnant.
- Kairos (appeals to timeliness) impresses the reader with your attunement to the situation. This should be practiced especially in the introduction, but it can appear throughout the essay as you engage with research and other voices that have recently weighed in on the topic.
All of these appeals are already happening, whether or not they’re recognized. If they are missed, the audience will often use them against you, judging your essay as not being personable enough (pathos), or not in touch with commonly accepted values (ethos), or out of touch with what’s going on (kairos). These non-logical appeals aren’t irrational. They are crucial components to writing that matters.
Argument Outline Exercise
To get started on your argument essay, practice adopting from of the outlines from this Persuasive Essay Outline worksheet .


1.16: Progressive Rock
Progressive Rock
Progressive Rock music is a form of rock in which elements of ‘art music’ such as classical music are incorporated in with rock elements. Though each progressive rock group vary widely from one to the next, they fall very roughly into three categories.
1) The most basic type of progressive rock is simply the addition of classical orchestral instruments (violins, cellos, etc.) into a rock setting, an extension of what producers George Martin and Phil Spector had been doing. Groups such as the Moody Blues used the mellotron (a keyboard that emulates the sound of orchestral instruments) to recreate the recordings they made with full orchestras.
2) A more advanced style came through groups such as Yes that wrote complex multi-movement works common in the classical music world. These pieces were often quite elaborate and intricately composed, and it was not uncommon for a complete ‘piece’ to take up an entire side of a vinyl record.
3) A more experimental style of prog rock was the use of “musique concrète”, or “concrete music”, based on ideas from modern classical composers in the avant-garde and electronic areas. The idea is that composers would use tape recordings of non-musical sound and organize them, via audio tape, into a musical composition. Sounds such as trains, clocks ticking, animal noises, or cash registers were all fair game. Pink Floyd explored this with the electronic sound collage work that permeated many of their albums, notably on Dark Side of the Moon (1973).
Rock Groups with Orchestra and the Mellotron
The Moody Blues incorporated the classical orchestra into their sound in 1967, featured on recordings such as “Nights in White Satin”. They used an electronic instrument called the Mellotron to emulate the orchestral timbres on their recordings. Soon after, the Mellotron showed up throughout popular recordings and was picked up, in particular, by progressive rock groups.
Genesis
Genesis also incorporated orchestral effects via the mellotron into their music. Additionally, they performed elaborate music and developed elaborate an stage act involving costume and character changes for singer Peter Gabriel. Genesis reached their theatrical peak with the double concept album The Lamb Lies Down on Broadway in which Gabriel plays a character that goes on a surrealistic journey of self-discovery. Gabriel left the group to pursue a solo career shortly afterwards, encountering great commercial and artistic success through the 1980s.
Drummer Phil Collins replaced Gabriel on vocals, continuing in the progressive rock vein with the album Trick of the Tail (1976). As time went on, the theatrical element of Genesis as well as the progressive nature of the music became less important as the group pursued a more commercial pop direction into the 1980s and encountered enormous success with Phil Collins as their primary vocalist. “Invisible Touch” (Listening Examples 16.2) from 1986 was one of the group’s biggest commercial successes, being their first and only No. 1 hit in the United States. Formally the song is not representative of their progressive rock style; rather, it uses a tried and true popular song form we are very familiar with at this point. Examine an excerpt of the lyrics below:
But thinking nothing, nothing could go wrong, ooh now I know
She has a built in ability
To take everything she sees
And now it seems I’m falling, falling for her
She reaches in, and grabs right hold of your heart
She seems to have an invisible touch, yeah
But she crawls under your skin
You’re never quite the same, and now I know
She’s got something you just can’t trust
And it’s something mysterious
And now it seems I’m falling, falling for her
She reaches in, and grabs right hold of your heart
She seems to have an invisible touch, yeah
It takes control and slowly tears you apart
The live version of “Watcher of the Skies” by Genesis in Ch. 16 Listening Examples is a perfect example progressive rock, featuring the use of synthesized orchestral sounds combined with rock instruments and a theatrical performance by lead singer Peter Gabriel. Listen as to how the vocals have a different feel rhythmically when compared to the rhythmic figure the band plays to accompany Gabriel.
Yes
Yes formed in 1968 and became one of the first and longest lasting progressive rock groups. They used multi-movement classical structures in their works, virtuosic instrumental playing, and used full group vocal harmonies. Early on, the group used synthesizers to emulate an orchestral sound, but their music developed to focus on the members’ technical skills.
Their fourth album Fragile featured each member taking turns as the featured performer on different tracks in addition to full group tracks.Their fifth and sixth albums, Close to the Edge and Relayer made use of the classical “suite” form in which a single piece was made up of multiple movements, and lasted much longer than a standard rock song.
Many personnel changes occurred, and the group broke up and reformed many times. They have been back together since 2008.
Listening Examples 16.2
Genesis: “Watcher of the Skies” (1973). “Invisible Touch” (1986) indicative of the band’s pop direction in the 1980s. “Entangled” (from Trick of the Tail ) is an example of the beginning of the Phil Collins-led era of Genesis and showcases the interesting musical textures the group was capable of. The music features three guitars and glockenspiel (a metallic pitched percussion instrument). Bass sounds are produced through organ bass pedals played with the feet. Collins still performed on drums periodically, but for the most part became primarily a vocalist.
Yes: “And You And I” live 1972. Listen for how the band goes through a number of contrasting musical sections. Some of these sections are purely instrumental while others feature vocals. The instrumental sections maybe be slow and minimal with a keyboard playing a single sustaining chord, or they may be complex and full of pre-written parts. The vocal sections sometimes feature the lead vocals of Jon Anderson and sometimes feature full sounding group vocals. Another example is of “Close to the Edge” .
King Crimson
King Crimson formed in 1969 by the leader and only constant member guitarist Robert Fripp. Fripp brought together instrumental virtuosity, avant-garde electronics, atonality, jazz and improvisation, and colorful instrumentation into a very intense and dark version of progressive rock. The group went through many lineup changes throughout the 1970s until Fripp disbanded Crimson in 1974 to focus on his experimental electronic music with composer Brian Eno until reforming the group in 1981.
The new version of the group featured Bill Bruford (who had been in the 70s group) on drums, guitarist/vocalist Adrian Belew, and bass/stick player Tony Levin. This group had an updated sound which they combined with the dark intensity of the 70s sound. The dual guitars and the new “Stick” (an instrument which uses two handed tapping on the strings) created complex rhythmic interplay reminiscent of classical minimalism. Belew added new life to the group as an energetic frontman/vocalist, and Fripp used new technology such as the guitar synthesizer in this new version of the group. Fripp disbanded the group again in 1984, and regrouped again in the mid 1990s. As of 2013 they have reformed with a new lineup featuring three drummers, woodwinds, and a new singer who has replaced Adrian Belew.
Listening Examples 16.2
King Crimson: “Red” (1974) is instrumental, relying on the electric guitar for the primary theme of the music. It is dissonant and reminiscent in some ways of modern classical works but features distorted electric guitars and rock aggression.
- “Elephant Talk” 1981
- “Frame by Frame” live 1984
Emerson, Lake, and Palmer
Emerson, Lake, and Palmer formed in 1970 as a progressive rock “power trio” of sorts. Consisting of keyboards/synths, guitar/bass, and drums, this trio made a sound much larger than most trios could make through the use of multiple keyboards and a plethora of percussion, obtaining an almost orchestral sound. ELP is well known for their reinterpretations of extended classical works and filtering them through rock instrumentation and rock aggression. Keith Emerson was classically trained on piano and brought an authentic touch to the music. “Fanfare for the Common Man” is a rock variation on the classic and timeless composition written by American composer Aaron Copland. ELP performs sections of the melody and intersperses rock and roll sections throughout, including an extended synthesizer solo.
Rush
Rush formed in Canada in the early 1970s as a power trio (Guitar, Bass, Drums) to play Cream and Led Zeppelin style hard rock. Originally formed by Alex Lifeson (Guitar), and Geddy Lee (Bass and vocals), drummer/lyricist Neil Peart joined later in 1974. With the album Fly By Night (1975) they began to incorporate extended multi-movement classical forms into their hard rock.
Their music was distinct from other progressive rock groups in that it was considerably heavier and rooted in the riff-based style of groups such as Led Zeppelin. Also, the voice of Geddy Lee is highly distinct for its high range. Although they occasionally use synthesizers and different percussion instruments such as the glockenspiel, Rush sticks primarily to the basic guitar, bass, and drums sound.
Pink Floyd
Originally a psychedelic rock group, Pink Floyd was forced into a new direction with the departure of singer/guitarist/primary songwriter Syd Barrett. The remaining members were Roger Waters (bass), Richard Wright (keyboards) and Nick Mason (Drums). Waters would grow to become the groups primary creative force, though all members gave creative contributions. Barret was replaced by guitarist/singer David Gilmour, and the band’s sound changed as the other members became more creatively competent.
Important features of Pink Floyd’s music was their use of sound effects and the construction of sound collages with prerecorded sounds in combination with their songs, and the long form compositions comprised of multiple smaller parts. Pieces such as “Saucerful of Secrets” (1968), “Atom Heart Mother” (1970) and “Echos” (1971) would take up an entire side of a record (or most of it), and were often epic in scope. “Atom Heart Mother” was structured into multiple movements much like the suite-style forms used by Yes and other groups and utilizes an orchestra along with the band, while “Saucerful of Secrets” makes extensive use of studio effects and unusual electronic sounds.
Waters had the idea for a concept album based on his own experience growing up without a father, and the album turned into one of the biggest selling albums of all time, The Dark Side of the Moon. (1973) The album makes use of prerecorded, non-musical sounds, called musique concrète ( concrete music ) that relate thematically to the lyrics. “Time” includes the sounds of clocks ticking and alarms ringing, while “Money” (Listening Examples 16.3, below) features rhythmically organized cash registers clicking and coins falling. “Money” also happens to be one of the most popular tracks on the album, notable for the fact that features a seven-beat pattern in the bass riff rather than the usual three or four beat patterns. Many of the songs on the album feature spine-tingling blues-based guitar solos from David Gilmour, a guitarist who focuses more on lyricism and voice-like expression on his guitar.
Their next album Wish You Were Here (1975) was a tribute to Syd Barrett who had since been living as a recluse due to mental illness. Animals (1977) takes a cynical view of humanity based on George Orwell’s book Animal Farm (1945) and features a mix of epic, heavy songs including the guitar-led epic “Dogs”. The Wall (1979) took a pessimistic view on modern society. “Another Brick in the Wall (Part 2)” talks of an education system that restricts freedom of thought. Both Animals and The Wall were primarily composed by Roger Waters, who by this time was exerting more and more creative control over the band’s output.
After The Final Cut (1983) Waters separated from the band and a legal war ensued over the use of the name Pink Floyd and of other elements. The other band members continued, however, using the name and remained very successful. The group reunited for one concert in 2005 at Live 8 before Richard Wright passed away in 2008.
Frank Zappa
Frank Zappa (1940-1993) was a Los Angeles-based composer, songwriter, producer, guitarist, vocalist, businessman, filmmaker, and leader of many groups including the Mothers of Invention. He stands alone in the world of popular music as an artist that crossed between genres, from classical to rock, jazz to humor, Doo-Wop to Avant-Garde electronic music. He was an extremely prolific artist with an incessant energy devoted to creating, and his body of work is vast.
Zappa incorporated a huge variety of instruments (think Phil Spector) and made productions that to this day remain completely unique. Sound effects are prominent, segues between songs occur often, and meticulously composed material is evident. Often vocals are modulated to sound high pitched, or otherwise bizarre.
Unusual instruments are showcased in the music of the Mothers. Orchestral percussion augments the sound of the drum set, wind instruments such as oboe or bassoon are not uncommon, and electronic sounds created in the studio are utilized. Some members of the group were highly accomplished, classically trained instrumentalists. In the live setting, Zappa served as conductor and leader as well as a guitarist, composer, and singer. Often times, Zappa conducted the band in an improvised context, telling them through hand signals what kind of sounds to play, how fast or slow, and when to transition into a composed section of music.
Zappa disbanded the original Mothers of Invention in 1969 mainly because Zappa was unable to continue paying the band member’s salaries, but also due to the fact that he wanted players who could read music and play some of the more difficult parts he was writing. The first album he released as a solo artist was Hot Rats (1969), a largely instrumental album that showcased both Zappa’s compositions and his unique guitar solos. It also featured the skills of keyboard/wind player Ian Underwood, a member of the original Mothers. The first track from the album is “Peaches en Regalia” and features layers over overdubbed guitar, keyboard, and saxophone lines. The music is instrumental, upbeat, and complex, though it is full of melodic hooks and has an upbeat, joyous feeling.
Zappa’s band again continued to evolve into the mid to late 1970s to include younger musicians such as drummer Terry Bozzio and singers Ray White and Ike Willis. His song “The Black Page” (see Listening Examples 16.3 below) became notorious for its complexity of rhythm, requiring considerable practice and technique. The song features extremely complex rhythms over top of a 4-beat pattern, and Zappa even made a danceable “Disco” version called “The Black Page No. 2” which highlights the 4-beat pattern and simplifies some of the complex rhythms. He continued writing satirical and crude pop songs as well. Around this time, business relations with Warner Brothers (with whom Zappa had been with for a number of years) began to deteriorate. He intended to release a 4-Disc record that included works for orchestra, complex instrumentals, and standard rock songs, but WB refused, instead releasing a number of single albums without Zappa’s consent. By the early 80s he was running his own label Barking Pumpkin Records and releasing his own music as an independent recording artist.
David Bowie
David Bowie – (Born David Jones, 1947-2016) Was inspired by the Beats as a teenager and began playing jazz and rhythm and blues. Inspired by beat poet Allen Ginsberg who demanded equality for homosexuals, Jones developed an androgynous image. He changed his name to David Bowie to distinguish himself from popular singer Davy Jones, and he developed a glittery space-age character known as Ziggy Stardust. Bowie doesn’t stick to one particular style, and his image is the primary reason for his “glitter rock” association.
Queen
Queen formed in 1971 with a standard hard-rock lineup of Freddie Mercury (vocals), Brian May (guitar), John Deacon (bass), and Roger Meadows-Taylor (drums).
Associated with “glitter rock” more for their androgynous visual image than for their music (like David Bowie), with vocalist Freddie Mercury wearing makeup and glittery outfits, and the band’s name itself suggests the androgynous association. While their music was hard-rock, the sound approached progressive rock with the use of sophisticated classical-style arrangements in the overdubbed guitar and vocal lines. The effect is of a string section or a choir and adds to the power of the music without actually using an orchestra or a choir. Freddie Mercury died in 1991, effectively ending the group, though they reunited in 2004 with different members.
The song “Bohemian Rhapsody” ( Ch. 16 Listening Examples ) is modeled after the operetta, and is structured as such with many sections, going beyond the standard rock song format. At one point the piece uses antiphonal choruses, a classical technique that is essentially call and response between a solo singer and a group of singers.
Listening Examples 16.3
Pink Floyd:
Rush: “Tom Sawyer” . Notice the unusual rhythm of the melodic “hook” played by the Geddy Lee on the synthesizer at 1:33. The line uses an unusual time: 7/8. A practical way to think about this unusual timing would be to describe it as a standard 4 beat pattern where the second half of the beat is deleted. So if standard 4/4 time is 1& 2& 3& 4& – 1& 2& 3& 4& etc, 7/8 would go as follows: 1& 2& 3& 4 – 1& 2& 3& 4 (Notice that the count goes directly from 4 to 1, no & is present, so the offbeat of the 4th beat is removed.)
Frank Zappa: “The Black Page” l ive and played by me on guitar to show the unusual technique required
Queen: “Bohemian Rhapsody”