void setup(){
  pinMode(23, OUTPUT);
}

void loop(){
  tone(23, 261.63);//Dó
  delay(1000);
  tone(23, 293.66);//Ré
  delay(1000);
  tone(23, 329.63);//Mi
  delay(1000);
  tone(23, 349.23);//Fá
  delay(1000);
  tone(23, 392.00);//Sol
  delay(1000);
  tone(23, 440.00);//La
  delay(1000);
  tone(23, 493.88);//Si
  delay(1000);
}