#define buzzer 17

const int button_pins[]  = {32,33,25};
const int buttonTone[]  =  {262, 294, 330}
int pitch=0;

void setup() {
 pinMode(buzzer, OUTPUT);
 digitalWrite(buzzer, LOW);

 for(i = 0; i < 3; i++){
  pinMode(button_pins[i], INPUT_PULLUP);
 }
}

void loop() {
 for(int i = 0; i < 3; i++){
  if(digitalRead(button_pins[i] == LOW) {
    pitch = buttonTone[i]
  })
 }
 if(pitch){
  tone(buzzer, pitch)
 }
 else
 noTone(buzzer);
}