#include "pitches.h"

#define SPEAKER_PIN 8

const uint8_t buttonPins[] = {12,11,10,9,7,6,5,4};

const int buttonTones[] = { NOTE_C4, NOTE_D4, NOTE_E4, NOTE_F4, NOTE_G4, 
NOTE_A4, NOTE_B4, NOTE_C5 };

const int numTones  = sizeof(buttonPins)/sizeof(buttonPins[0]);

void setup() {
  // put your setup code here, to run once:
  for(uint8_t i=0; i<numTones; i++){
    pinMode(buttonPins[i], INPUT_PULLUP);
  }
  pinMode(SPEAKER_PIN, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  int pitch = 0;
  for(uint8_t i=0; i<numTones; i++){
    if(digitalRead(buttonPins[i]) == LOW){
      pitch = buttonTones[i];
    }
  }
  if(pitch){
    tone(SPEAKER_PIN, pitch);
  }
  else {
    noTone(SPEAKER_PIN);
  }
}