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How does a piano produce sound when a key is pressed?
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stringed instrument
A Japanese musician plucking the strings of a koto with the right hand to generate a pitch and pressing the strings with the left hand to alter the tone.
When a key on a piano is pressed, it initiates a mechanical process that produces sound through the following steps:
- Activation: The key movement triggers an internal mechanism known as the action. This mechanism accelerates a felt-covered hammer toward a specific string or set of strings.12
- Striking: The hammer strikes the string, causing it to vibrate. Because the hammer hits the string rather than plucking it, the piano is categorized as both a chordophone and a percussion instrument.1
- Amplification: The vibrations of the string are transmitted via a bridge to a soundboard. The soundboard vibrates in response, significantly amplifying the faint sound produced by the string alone.3
- Damping: When the key is at rest, dampers silence the strings. Pressing the key lifts the damper, allowing the string to vibrate freely until the key is released.2
The pitch produced depends on the length and thickness of the string struck, with shorter, thinner strings producing higher pitches and longer, thicker strings producing lower pitches.1