user49762: The idea is when a switch is pushed, the corresponding tone will be played as well as lighting up the corresponding LED. I have the circuit set up to where each array matches another, for example Switch one will play tone 1 and light LED 1. When the switch is released the LED turns off and the tone no longer plays.  
However I have to use an Array for the sketch instead of declaring each individual switch, led, and tone.  My issue is when I compile the code, I get the error message "i" is not declared.  Not sure where my error is within the for loop in the setup portion of the sketch.  
I tried following the example from the Exploring Arduino web page but it did not help.
#define NOTE_C   262 //HZ
#define NOTE_D   294 //HZ
#define NOTE_E   330 //HZ
#define NOTE_G   392 //HZ
#define NOTE_A   440 //HZ

const int SPEAKER = 9;   //speaker on pin 10
int LED[5] = {13, 12, 11, 10, 8};   //led pins
int ledcount = 5;
int buttonState; 
int buttonState1;
int buttonState2;
int buttonState3;
int buttonState4;

//Button Array
int Buttons[5]= {3, 4, 5, 6, 7};
int ButtonCount = 5;
const int numButtons = sizeof(Buttons) / sizeof (Buttons[0]);

//Tone Note Array
int Notes[5] = {NOTE_C, NOTE_D, NOTE_E, NOTE_G, NOTE_A};

void setup()
{
  for (int i = 0; i < sizeof (Buttons) / sizeof(Buttons[0]); i++){
  pinMode(Buttons[], INPUT);
}
  for (int i = 0; i < sizeof (LED) / sizeof (LED[0]); i++);{
  pinMode(LED[], OUTPUT);
}
  for (int i = 0; i < numButtons; i++){
  pinMode(Buttons[i], INPUT);
  debouncer[i].attach(Buttons[i]);
  debouncer[i].interval(100);
}
  buttonState = digitalRead(Buttons[0]);
  buttonState1 = digitalRead(Buttons[1]);
  buttonState2 = digitalRead(Buttons[2]);
  buttonState3 = digitalRead(Buttons[3]);
  buttonState4 = digitalRead(Buttons[4]);
}


void loop()
{


  if (buttonState == HIGH)
  { tone(SPEAKER, Notes[0]);
  digitalWrite(LED[0], HIGH);
  }
  else if (buttonState1 == HIGH)
  {tone(SPEAKER, Notes[1]);
  digitalWrite(LED[1], HIGH);
 }
  else if (buttonState2 == HIGH)
  {tone(SPEAKER, Notes[2]);
  digitalWrite(LED[2], HIGH);
 }
  else if (buttonState3 == HIGH)
  {tone(SPEAKER, Notes[3]);
  digitalWrite(LED[3], HIGH);
 }
  else if (buttonState4 == HIGH)
  {tone(SPEAKER, Notes[4]);
   digitalWrite(LED[4], HIGH);
 }

  else
 {
  digitalWrite(LED[5], LOW);
  noTone(SPEAKER);
 }
}


user4143: You have a rogue ; here:
  for (int i = 0; i < sizeof (LED) / sizeof (LED[0]); i++);{
  pinMode(LED[], OUTPUT);                                 ^------HERE
}

That is terminating the for, making it empty, and the following block is a completely different scope.
Another thing I spotted - you aren't putting i into your array index LED[] (should be LED[i]).  The same is true with Buttons[].
However, on a different subject, this:
buttonState == digitalRead(Buttons[0]);
buttonState == digitalRead(Buttons[1]);
buttonState == digitalRead(Buttons[2]);
buttonState == digitalRead(Buttons[3]);
buttonState == digitalRead(Buttons[4]);

is pretty meaningless.  You are comparing values and throwing away the result.
In a similar vein:
if (buttonState = Buttons[0])

stores the current value of Buttons[0] into buttonState and succeeds if Buttons[0] is anything other than 0.  The same goes for all the others.
You need to sort out your comparisons (==) and your assignments (=) and also sort out what you think you are doing with all those buttonStates at the top of loop.

49762: <p>The idea is when a switch is pushed, the corresponding tone will be played as well as lighting up the corresponding LED. I have the circuit set up to where each array matches another, for example Switch one will play tone 1 and light LED 1. When the switch is released the LED turns off and the tone no longer plays.  </p>

<p>However I have to use an Array for the sketch instead of declaring each individual switch, led, and tone.  My issue is when I compile the code, I get the error message "i" is not declared.  Not sure where my error is within the for loop in the setup portion of the sketch.  </p>

<p>I tried following the example from the Exploring Arduino web page but it did not help.</p>

<pre><code>#define NOTE_C   262 //HZ
#define NOTE_D   294 //HZ
#define NOTE_E   330 //HZ
#define NOTE_G   392 //HZ
#define NOTE_A   440 //HZ

const int SPEAKER = 9;   //speaker on pin 10
int LED[5] = {13, 12, 11, 10, 8};   //led pins
int ledcount = 5;
int buttonState; 
int buttonState1;
int buttonState2;
int buttonState3;
int buttonState4;

//Button Array
int Buttons[5]= {3, 4, 5, 6, 7};
int ButtonCount = 5;
const int numButtons = sizeof(Buttons) / sizeof (Buttons[0]);

//Tone Note Array
int Notes[5] = {NOTE_C, NOTE_D, NOTE_E, NOTE_G, NOTE_A};

void setup()
{
  for (int i = 0; i &lt; sizeof (Buttons) / sizeof(Buttons[0]); i++){
  pinMode(Buttons[], INPUT);
}
  for (int i = 0; i &lt; sizeof (LED) / sizeof (LED[0]); i++);{
  pinMode(LED[], OUTPUT);
}
  for (int i = 0; i &lt; numButtons; i++){
  pinMode(Buttons[i], INPUT);
  debouncer[i].attach(Buttons[i]);
  debouncer[i].interval(100);
}
  buttonState = digitalRead(Buttons[0]);
  buttonState1 = digitalRead(Buttons[1]);
  buttonState2 = digitalRead(Buttons[2]);
  buttonState3 = digitalRead(Buttons[3]);
  buttonState4 = digitalRead(Buttons[4]);
}


void loop()
{


  if (buttonState == HIGH)
  { tone(SPEAKER, Notes[0]);
  digitalWrite(LED[0], HIGH);
  }
  else if (buttonState1 == HIGH)
  {tone(SPEAKER, Notes[1]);
  digitalWrite(LED[1], HIGH);
 }
  else if (buttonState2 == HIGH)
  {tone(SPEAKER, Notes[2]);
  digitalWrite(LED[2], HIGH);
 }
  else if (buttonState3 == HIGH)
  {tone(SPEAKER, Notes[3]);
  digitalWrite(LED[3], HIGH);
 }
  else if (buttonState4 == HIGH)
  {tone(SPEAKER, Notes[4]);
   digitalWrite(LED[4], HIGH);
 }

  else
 {
  digitalWrite(LED[5], LOW);
  noTone(SPEAKER);
 }
}
</code></pre>
 4143: <p>You have a rogue <code>;</code> here:</p>

<pre><code>  for (int i = 0; i &lt; sizeof (LED) / sizeof (LED[0]); i++);{
  pinMode(LED[], OUTPUT);                                 ^------HERE
}
</code></pre>

<p>That is terminating the <code>for</code>, making it empty, and the following block is a completely different scope.</p>

<p>Another thing I spotted - you aren't putting <code>i</code> into your array index <code>LED[]</code> (should be <code>LED[i]</code>).  The same is true with Buttons[].</p>

<p>However, on a different subject, this:</p>

<pre><code>buttonState == digitalRead(Buttons[0]);
buttonState == digitalRead(Buttons[1]);
buttonState == digitalRead(Buttons[2]);
buttonState == digitalRead(Buttons[3]);
buttonState == digitalRead(Buttons[4]);
</code></pre>

<p>is pretty meaningless.  You are comparing values and throwing away the result.</p>

<p>In a similar vein:</p>

<pre><code>if (buttonState = Buttons[0])
</code></pre>

<p>stores the current value of Buttons[0] into buttonState and succeeds if <code>Buttons[0]</code> is anything other than 0.  The same goes for all the others.</p>

<p>You need to sort out your comparisons (<code>==</code>) and your assignments (<code>=</code>) and also sort out what you think you are doing with all those buttonStates at the top of loop.</p>
