void setup() {
  pinMode(11, INPUT);
  pinMode(10, INPUT);
  pinMode(9, INPUT);
  pinMode(8, INPUT);
  pinMode(7, INPUT);
  pinMode(6, INPUT);
  pinMode(5, INPUT);
  pinMode(4, INPUT);
  pinMode(0, OUTPUT);
}

void loop() {
  if (digitalRead(11) == HIGH) {
    tone(0, 261); // Play C4 
    while (digitalRead(11) == HIGH) { 
    }

    noTone(0);
  }
  if (digitalRead(10) == HIGH) {
    tone(0, 293); // Play D4 
    while (digitalRead(10) == HIGH) {
    }
    noTone(0); 
  }
  if (digitalRead(9) == HIGH) {
    tone(0, 329); // Play E4
    while (digitalRead(9) == HIGH) {
    }
    noTone(0); 
  }
  if (digitalRead(8) == HIGH) {
    tone(0, 349); // Play F4
    while (digitalRead(8) == HIGH) {
    }
    noTone(0);
  }
  if (digitalRead(7) == HIGH) {
    tone(0, 392); // Play G4
    while (digitalRead(7) == HIGH) {
    }
    noTone(0); 
  }
  if (digitalRead(6) == HIGH) {
    tone(0, 440); // Play G4
    while (digitalRead(6) == HIGH) {
    }
    noTone(0); 
  }
  if (digitalRead(5) == HIGH) {
    tone(0, 494); // Play G4
    while (digitalRead(5) == HIGH) {
    }
    noTone(0); 
  }
  if (digitalRead(4) == HIGH) {
    tone(0, 523); // Play G4
    while (digitalRead(4) == HIGH) {
    }
    noTone(0); 
  }
  delay(10);
}