P.47 (Add Methods to Control Key Up and Down)

public void whiteKeyDownUp() {
  setImage("white-key-down.png");
  Greenfoot.playSound(sound);
  Greenfoot.delay(15);
  setImage("white-key.png");
}

public void blackKeyDownUp() {
  setImage ("black-key-down.png");
  Greenfoot.playSound(sound);
  Greenfoot.delay(15);
  setImage ("black-key.png");
}