Programming Arduino Uno using a 2 dimentional array issue

void loop() {
  int potVal = map(analogRead(A2), 0, 1024, 0, 3);
  for (int i = 0; i < numberOfButtons; i++) {
    checkButton(potVal,i);
  }
}

void checkButton(int scaleNum,int buttonNum)
{
  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin[buttonNum]);

  // check if the pushbutton is pressed. If it is, the buttonState is HIGH:
  if (buttonState == HIGH) {
    digitalWrite(ledPin[buttonNum], HIGH);
    tone(speaker, notes[scaleNum][buttonNum]);                 // play the note
    delay(100);                       // wait for 1/10th of a second
  } else {
    digitalWrite(ledPin[buttonNum], LOW);
    noTone(speaker);                  // stop playing the note
  }
}