How it began
The Banu Musa were three brothers, scholars at the House of Wisdom in Baghdad, in present-day Iraq, under the Abbasid Caliphate. About 850 they published the Book of Ingenious Devices, a large illustrated work commissioned by Caliph al-Mamun that described about one hundred devices. In a separate treatise they described an instrument which plays by itself. Their designs included a water-powered organ and an automatic flute player.
Before it existed
The brothers drew on Hellenistic knowledge. Their self-playing instrument built on an automatic wind instrument attributed to Archimedes and a hydraulic device attributed to Apollonius. The Book of Ingenious Devices combined such Greek sources with new ideas of their own, including automatic controls, conical valves and other hydraulic devices.
How it works
Air pushed by a hydraulic pump was compressed in a sphere and fed to a flute. The flute had nine holes, opened and closed by eight levers. The ends of the levers touched raised pins fixed on the surface of a revolving cylinder, so the arrangement of pins set the melody. The organ played interchangeable cylinders automatically, so a different cylinder gave a different tune.
What lasted
The History of Information calls the organ the earliest known mechanical musical instrument and says the flute player appears to have been the first programmable machine. Charles B. Fowler wrote that the cylinder with raised pins remained the basic device to produce and reproduce music mechanically until the second half of the nineteenth century. The book later influenced engineers including al-Jazari.
Where it stands today
Scholars describe the flute player as an early programmable instrument that could be programmed much like the punched card looms of the 19th century. Reconstructions were shown in the exhibition Allah's Automata at ZKM, the Center for Art and Media in Karlsruhe, Germany, and documented in a book of the same name covering the period 800 to 1200.
