A musical keyboard is the set of
adjacent depressible levers or keys on a
musical instrument,
particularly the piano.
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.
Depressing a key on the keyboard causes the instrument to produce sounds, either
by mechanically striking a string or tine (piano, electric piano, clavichord);
plucking a string (harpsichord); causing air to flow through a pipe (organ); or
strike a bell (carillon). On electric and electronic keyboards, depressing a key
connects a circuit (Hammond organ, digital piano, synthesizer). Since the most
commonly encountered keyboard instrument is the piano, the keyboard layout is
often referred to as the "piano keyboard".