The Playing Mechanism
Explore the Playing Mechanism
Move the mouse over the picture on the right to highlight different components of the playing mechanism. Click on a highlighted part to learn more about it. Also, be sure to watch the animation of the action in motion, and be sure to try the "action puzzle" - links are located at the left of each page.
A Complex Chain Reaction
The playing mechanism consists of several main components that work together in a complex chain of events in order to set the string vibrating:
- The keyboard is comprised of 88 individual keys which are mounted on the keyframe. Each key controls its own action and damper assembly.
- The action is the system of levers responsible for throwing the hammer at the string when the key is depressed.
- The damper is the part designed to silence the strings when they are not being played.
- The pedals can be activated to affect the tone of the piano.
Flanges and Rails
The playing mechanism consists of a system of levers designed to transmit the energy from the pianist’s fingers to the string. Many of the moving parts of the mechanism are mounted on hinges are called flanges. The moving part fits inside the flange, and is held in place by a small center pin. This center pin rotates in a felt-lined hole in the flange called the bushing. The bushing acts as cushion to ensure silent operation of the moving part. Wool felt is also used as a cushion in other parts of the playing mechanism, such as the keyboard and damper.
There are many rails found in the playing mechanism of the piano. A rail is a bar which extends the entire keyboard width of the playing mechanism. The purpose of a rail is to support a common body of parts. For example – the damper guide rail supports and aligns all the dampers. The 88 keys pivot over the balance rail, and most of the moving parts of the action rotate on flanges attached to some type of rail. The rails are usually made of wood, although certain manufacturers use aluminum alloy for some of the rails. The images of the playing mechanism on this site are based on the Yamaha action, which uses several metal rails.