How Pianos Work

Pianos are quite possibly the most well know instrument in music. It seems that virtually everyone knows how to play at least Mary Had a Little Lamb. But very few people actually know how pianos work.

Pianos are an incredibly complicated instrument. If you have ever looked into a piano you have probably seen the hammers that hit the strings making sound. If you think that the hammer is simply attached to the key (as I once thought) you are wrong. There is a very complex mechanism that makes the whole thing work.

Please note that this article talks specifically about upright pianos. Although grand pianos are not exactly the same, they are quite similar. I would still suggest doing research on them if you want to know more.

Here are some of the most important parts of the piano:

  • Keys What is pressed by the pianist
  • Action The mechanism transfers the energy from the key to the hammer
  • Damper The thing that keeps the strings from producing sound when the player doesnt want them to.
  • Strings The thing that makes the sound
  • Hammer The thing that hits the strings to produce the sound
  • Soundboard The thing that amplifies the sound.

The most complicated of these is by far the action, and this is what I will be focusing on the most. The action is the mechanism by which energy is transfered from the key to the hammer and into the strings, which then vibrate. As I have said, it is very complicated. I am not a piano expert or technician, so I will not provide a provide a perfect explanation, but I will do my best to explain it.

The image to the right shows the (slightly simplified) action of an upright piano. As you can see, it is rather complicated.

When you press a key it rocks and lifts on the back, pushing on the sticker. The sticker pushes on the whippen which in turn presses on the jack. The jack preses on the butt of the hammer, which begins to pivot towards the string.

When the hammer is halfway to the string the damper spoon engages with the bottom of the damper, and pivots the entire damper away from the string.

When the hammer has almost reached the string, the end of the jack hits the set-off button (also called the regulating button), and the jack stops pushing on the hammer, but the whippen continues moving up. The jack pivots and slips out from under the hammer, which continues under its own inertia and strikes the string, immediately bouncing off. The balance hammer is caught by the back check, and held there as long as the key is being depressed.

Meanwhile, the vibration of the string is carried through the bridge (not pictured) and into the sound board, which amplifies the sound.

When the key is released, the whole thing resets. The damper again presses on the string, stopping the sound and the jack returns to its original position. The key is ready to be sounded again.

The damper pedal is sometimes used to allow the strings to continue producing sound even after the key is released. It simply removes all of the dampers from the strings.

I hope this has given you an idea of how the piano works. As I said, it is incredibly complicated and very few people fully understand it. It is not incredibly important to a piano player, but it is still quite interesting. You can find much more information by just typing how pianos work into Google.