#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 ( ) {
  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) ;
} 
}