#include "pitches.h"

#define SPEAKER_PIN 2


const uint8_t buttonPins[] = { 12, 11, 10, 9, 8, 7, 6, 5 };

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() {

  for (uint8_t i = 0; i < numTones; i++) {

    pinMode(buttonPins[i], INPUT_PULLUP);

  }

  pinMode(SPEAKER_PIN, OUTPUT);

}

void loop() {

  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);

  }

}