Organ (music)

In music, the organ (from Greek ὄργανον organon, "organ, instrument, tool")is a keyboard instrument of one or more pipe divisions or other means for producing tones, each played with its own keyboard, played either with the hands on a keyboard or with the feet using pedals. The organ is a relatively old musical instrument,dating from the time of Ctesibius of Alexandria (285–222 BC), who invented the water organ. It was played throughout the Ancient Greek and Ancient Roman world, particularly during races and games.During the early medieval period it spread from the Byzantine Empire, where it continued to be used in secular (non-religious) and imperial court music, to Western Europe, where it gradually assumed a prominent place in the liturgy of the Catholic Church. Subsequently it re-emerged as a secular and recital instrument in the Classical music tradition.

Overview
Pipe organs use air moving through pipes to produce sounds. Since the 16th century, pipe organs have used various materials for pipes, which can vary widely in timbre and volume. Increasingly hybrid organs are appearing in which pipes are augmented with electronic additions. Great economies of space and cost are possible especially when the lowest (and largest) of the pipes can be replaced.

Non-piped organs include the reed organ or harmonium, which like the accordion and harmonica (or "mouth organ") use air to excite free reeds.

Electronic organs or digital organs, notably the Hammond organ, generate electronically produced sound through one or more loudspeakers.

Mechanical organs include the barrel organ, water organ, and Orchestrion. These are controlled by mechanical means such as pinned barrels or book music. Little barrel organs dispense with the hands of an organist and bigger organs are powered in most cases by an organ grinder or today by other means such as an electric motor.
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