   in music, the organ (from greek á½ÏÎ³Î±Î½Î¿Î½ organon, "organ, instrument, tool")organon, henry george liddell, robert scott, a greek-english lexicon, at perseus project is a keyboard instrument of one or more divisions, each played with its own keyboard, played either with the hands or with the feet. the organ is a relatively old musical instrument in the western musical tradition,the organ developed from older musical instruments like the panpipe, therefore is not the oldest musical instrument. dating from the time of ctesibius of alexandria who is credited with inventing the hydraulis. it gradually assumed a prominent place in the liturgy of the catholic church. subsequently it re-emerged as a secular and recital instrument. ==overview==  pipe organs use wind moving through pipes to produce sounds. since the 16th century, pipe organs have used various materials of pipes, which can vary widely in timbre and volume. the pipes are divided into ranks and controlled by the use of hand stops and/or combination pistons. although the keyboard is not expressive as on a piano and does not affect dynamics (pressing a key only turns the sound on or off), some divisions may be enclosed in a swell box, allowing the dynamics to be controlled by shutters
Ancient_Greek_musical_instruments Keyboard_instruments Organs_(music)