The pipe organ was humanity's most complex machine until the telephone exchange
A pipe organ sounds by forcing pressurised air, called wind, through pipes chosen from a keyboard. Its ancestor ran on water pressure in ancient Greece, and by the 1600s it had become the most complicated device people had built, a title it held until telephone exchanges arrived in the late nineteenth century.
Every pipe plays one note in one tone colour, so pipes come in sets called ranks, each sharing a timbre and loudness across the keyboard's range. Controls called stops let the organist switch ranks on singly or blend them. Hands play one or more keyboards, known as manuals, and most organs add a pedalboard for the feet; each keyboard commands its own group of stops, all gathered at the console. Because the wind keeps flowing, a note lasts as long as the key is held, unlike a piano or harpsichord, whose sound starts fading at once. The range is vast, from portable instruments with a couple of dozen pipes and a single manual to giants with more than 33,000 pipes and seven manuals.
The story starts with the hydraulis of third-century BC Greece, which used the weight of displaced water in a sealed tank to push air. The name itself descends from the Greek organon, simply a tool or instrument, by way of the Latin organum, a small organ-like device heard at Roman circus games. By the sixth or seventh century AD Byzantine organs were fed by bellows. In 757 Emperor Constantine V sent one with great lead pipes to Pepin the Short, king of the Franks, and in 812 Pepin's son Charlemagne asked for one for his chapel at Aachen, which set the organ on its path into Western church music.
England's earliest well-documented organ, built at Winchester Cathedral in the tenth century, had 400 pipes, took two players and 70 men working the bellows, and could reportedly be heard across the city. From the twelfth century builders added varied tone colours, and by the seventeenth most sounds of the modern classical organ existed.
Organs now stand in churches, synagogues, concert halls, schools and private houses, serving sacred, classical, secular and popular music. In the early twentieth century they accompanied silent films in cinemas, played orchestral arrangements in civic auditoriums and graced wealthy homes, and the twenty-first century has brought a wave of new concert-hall installations. Their repertoire now covers more than 500 years.
Source: Pipe organ
