Definition: The “action” refers to the moving mechanism inside a piano that is activated when a key is depressed, which ultimately produces sound by striking a hammer against a string. The piano action is made up of numerous individual pieces – some very small and delicate – including (but certainly not limited to) the following:
- Hammer: Strikes a string when a key is depressed.
- Damper: A piece of soft cloth or felt that rests on a string when it’s not in use. When a key is depressed, a damper lifts off the string, allowing it to vibrate and create sound.
- Wippen: Piece between a key and a hammer, responsible for the upward motion of the hammer after a key is depressed.
- Jack: Between the key and hammer; set in motion by the wippen.