Musical keyboard
A musical keyboard is the set of adjacent depressible levers or keys on a musical instrument. Keyboards typically contain keys for playing the twelve notes of the Western musical scale, with a combination of larger, longer keys and smaller, shorter keys that repeats at the interval of an octave. Pressing a key on the keyboard makes the instrument produce sounds—either by mechanically striking a string or tine (acoustic and electric piano, clavichord), plucking a string (harpsichord), causing air to flow through a pipe organ, striking a bell (carillon), or activating an electronic circuit (synthesizer, digital piano, electronic keyboard). Since the most commonly encountered keyboard instrument is the piano, the keyboard layout is often referred to as the piano keyboard or simply piano keys.
This article is about keyboards on musical instruments. For instruments referred to as "keyboards", see Keyboard instrument.Keyboards with alternative sets of keys[edit]
There are some rare variations of keyboards with more or fewer than 12 keys per octave, mostly used in microtonal music, after the discoveries and theoretical developments of musician and inventor Julián Carrillo (1875–1965).
Some free-reed instrument keyboards such as accordions and Indian harmoniums include microtones. Electronic music pioneer Pauline Oliveros played one of these. Egyptian belly-dance musicians like Hassam Ramzy use custom-tuned accordions so they can play traditional scales. The small Garmon accordion played in the Music of Azerbaijan sometimes has keys that can play microtones when a "shift" key is pressed.