From hydraulis pipes to piano touch and synth desks
A keyboard is simply a row of finger levers, yet it drives instruments as different as the pipe organ, the celesta, the harpsichord and the synthesizer. The idea goes back to a Greek water organ of the third century BC, and the piano began as Bartolomeo Cristofori's 1698 harpsichord that could play both soft and loud.
What makes something a keyboard instrument is the way it is played, not the way it makes sound. The family therefore sweeps in wind instruments such as the pipe organ, pump organ and accordion; struck metal like the celesta, carillon and glasschord; plucked strings like the harpsichord, tangent piano and lautenwerck; bowed designs such as the hurdy-gurdy; hammered strings in the clavichord and piano; and electric machines from the electric piano to the mellotron. Carillons usually hang in the bell towers of churches or town halls.
The oldest known example is the hydraulis, an ancient Greek water-powered organ from the third century BC. Its keys were probably balanced, since the late fourth-century poet Claudian praised a player who unleashed huge roars with a gentle touch. For well over a thousand years the organ was the only keyboard instrument, and it often had buttons or big levers pushed with a whole hand rather than proper keys. Until the fifteenth century almost every keyboard had seven naturals to the octave.
The clavicymbalum, clavichord and harpsichord all appeared in the fourteenth century, the clavichord probably first, and they stayed common until the piano spread in the eighteenth. Cristofori's Italian invention, the gravicèmbalo con piano e forte, let players shape volume by how hard they struck each key. Today's piano, refined since the late nineteenth century, looks and sounds unlike the instruments Mozart, Haydn and Beethoven knew. The twentieth century added electromechanical devices such as the Ondes Martenot and, later, electronic keyboards.
In everyday speech a keyboard now usually means a synthesizer, arranger or workstation that turns key presses into electrical signals, often using sampling to imitate far more than piano tones, while still letting a sensitive player control phrasing, shading and articulation. Music historians use the word differently: in the eighteenth century harpsichord, clavichord and early piano competed for the same repertoire, so saying Mozart excelled at the keyboard deliberately leaves the instrument open.
Source: Keyboard instrument
