8 Parts of a Piano: How Pianos Produce Sound

The piano is a chordophone, or string instrument. Inside a piano’s frame, piano strings run across a soundboard. When a player presses piano keys, they trigger felted hammers to strike the strings. These hammer strikes cause the strings to vibrate, which produces the modern piano sound we recognize today. Due to its unusual anatomy, the piano can also be classified as a percussion instrument, but under the Hornbostel-Sachs system of classification, pianos are grouped with chordophones.

Though they differ in size and shape, all types of pianos—from concert grand pianos to upright pianos—have the same basic parts.

1. 1. Outer rim and lid: The outer rim of the piano is made from hardwood, often either maple or beech. A grand piano rim is cut to fit its soundboard, while vertical pianos called uprights have frames in the shape of a rectangular prism. Both these styles contain a wooden lid that covers the strings and the soundboard. The hardwood rim design of the modern piano was invented by C.F. Theodore Steinway, founder of the Steinway & Sons brand of pianos based in New York City.
2. 2. Inner frame: The inner frame of the piano is built from a heavy cast iron plate. This iron frame supports the soundboard and the hardwood pinblock. The pinblock contains brass guide screws, or agraffes, that keep strings properly spaced.
3. 3. Soundboard: A piano's soundboard is the wooden surface over which strings vibrate, mimicking the resonant properties of string instruments like the violin, cello, and guitar. High-quality piano soundboards are generally made out of Sitka spruce; budget pianos use plywood.
4. 4. Keyboard: The piano keyboard is the instrument's playing medium. The white keys are sometimes called "naturals" while the black keys are called "enharmonics." There are 88 keys on a standard piano keyboard. Piano keys are housed in a keyframe, which rests on a keybed. A keyslip runs across the front of the piano to keep this apparatus out of sight.
5. 5. Piano action: The piano action is a series of levers that connect piano keys to the hammers that strike piano strings. The piano action allows the player to produce a wide range of dynamics, depending upon the velocity with which they strike the piano keys. The piano's dynamic range sets it apart from earlier keyboard instruments like the harpsichord. Composers like Beethoven, Chopin, Schumann, and Liszt took full advantage of these dynamics when composing for piano.
6. 6. Strings: Piano strings run nearly the entire length of the instrument. They are made of tightly wound steel wire that runs from tuning pins on the pinblock to hitch pins at the back of the piano. Vibrating strings resonate in different ways depending on how they are struck by the piano action. Pianos are tuned by adjusting the tension of the strings.
7. 7. Dampers: Dampers are small wooden blocks with felt pads attached. They rest upon strings to prevent them from vibrating unless they are struck, in which case the damper is raised. The highest treble strings of a piano do not have dampers.
8. 8. Pedals: Most pianos have three pedals, but some have only two. The left pedal is called una corda, or soft pedal. It shifts the entire keyboard action slightly to the right, which softens the sound when strings are struck. The middle pedal is called the sostenuto pedal. It provides sustain for notes played when the pedal is activated, and it does this by moving the dampers away from the respective strings, allowing the strings to continue vibrating. The final pedal is alternately known as the damper pedal, the sustain pedal, and the sustaining pedal. When depressed, it lifts the dampers off all the strings to create a resonant sustain sound filled with overtones.

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