A keyboard instrument is a musical instrument played using a keyboard, a row of levers which are pressed by the fingers. The most common of these are the piano, organ, and various electronic keyboards, including synthesizers and digital pianos. Other keyboard instruments include celestas, which are struck idiophones operated by a keyboard, and carillons, which are usually housed in bell towers or belfries of churches or municipal buildings.
Today, the term keyboard often refers to keyboard-style synthesizers. Under the fingers of a sensitive performer, the keyboard may also be used to control dynamics, phrasing, shading, articulation, and other elements of expression—depending on the design and inherent capabilities of the instrument.
Another important use of the word keyboard is in historical musicology, where it means an instrument whose identity cannot be firmly established. Particularly in the 18th century, the harpsichord, the clavichord, and the early piano were in competition, and the same piece might be played on more than one. Hence in a phrase like "Mozart excelled as a keyboard player" the word keyboard is usefully noncommittal.
Much effort has gone into creating an instrument that sounds like the piano but lacks its size and weight. The electric piano and electronic piano were early efforts that, while useful instruments in their own right, did not convincingly reproduce the timbre of the piano. Electric and electronic organs were developed during the same period. More recent electronic keyboard designs strive to emulate the sound of specific make and model pianos using digital samples and computer models.