The Number System Explained!

How numbers can change the way you think about and play music

Lisa Witt - Nov 22, 2019





If you've watched many of my videos, or read many blog posts, you'll know that I use numbers a lot.


I'm not some math wizard.


I'm using something called the Number System (or Nashville Number System). I'll often get asked what the numbers mean, and why I use them.  So today I will answer all those questions.


But before I explain it, you need to know...


This will change everything!


I'm not exaggerating when I say that learning the Number System is one of the BEST things I've learned on the piano.


It's allowed me to memorize chord progression, create my own progressions and change keys really easily.


If you play in a band or at church, you need to know the Number System.


Ok great ... so what is it?


The Number System is simple. Every note in a scale has a number, and we use those numbers to talk about chords built from those notes.


Let's look at the C major scale. The notes go C-D-E-F-G-A-B and back to C:



So each one of those notes gets a number. C is 1, D is 2, etc. Notice top C is called 1 again (sometimes it's called 8 but we'll call it 1).


Easy, right? But not super useful -- just yet.


Chords are where the magic happens


The Number System becomes AMAZING when it's used to talk about chords. We can build a chord from ANY note in the scale (check out this lesson to learn more).


I'll show you some common chords so you can see what I mean.


C = 1 remember. So a C chord is also called a 1 chord. It looks like this:



You can see it's a simple chord built on the first note, or 1.


And you can do this for EVERY number in the scale. Think about the 5 chord. What's the 5th note in the C scale? G!


So the 5 chord is just a chord built from the 5th note. In the key of C, it's a G major chord:



The same is true for the other chords. Here's the 6 chord, it's an A minor chord:



And the 4 chord (F major):


Putting them together - chord progressions


Remember at the start of the post, I wrote 1-5-6-4? 


So now you know what those numbers mean, you can create a chord progression from them, in ANY key. In the key of C, we've just learned that the 1-5-6-4 chords are C major, G major, A minor, and F major.


But because the Number System can be used in any key, you could now play that same 1-5-6-4 in whatever key you choose.


Take the key of G major for example. The notes of the G major scale are G-A-B-C-D-E-F#-G. 


Now using the Number System we know that G is 1, A is 2, B is 3, etc.


So the 1-5-6-4 progression in G is G major, D major, E minor, C major.


For more on changing keys, check out this lesson.


But wait ... did you notice those weird symbols?


If you paid attention to the graphics above, you may have noticed that there are weird symbols above each chord.


Those are Roman numerals. We use Roman numerals in the Number System to tell us if the chord is MAJOR or MINOR. Regular numbers can't do that.


Here are the Roman numerals for all the numbers up to 7 in a major scale:



As you can see, some of them are in upper case, while others are lower case. The UPPER case means a MAJOR chord, and the LOWER case means a MINOR chord (or diminished for 7).


So in a major scale, we know that the 1 - 4 and 5 chords are all major chords. The 2 - 3 and 6 are minor chords, and the 7 is a diminished.


And that -- is the Number System!


Get comfortable with the numbers in different keys, and then listen to popular songs and try to hear the chord progressions they are using.


For more on the 1-5-6-4 progression, we have another lesson here.


Have fun!

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Hi, I'm Lisa Witt
