prepared piano history

John Cage developed the prepared piano in 1940 when he needed percussion sounds for a dance accompaniment but had only a grand piano available. He placed screws, bolts, rubber strips, and other objects between and on the piano strings, transforming the instrument into what he called "a percussion orchestra under the control of a single player." Each preparation changes the string's timbre, pitch, and sustain characteristics — a screw might produce a metallic ping, rubber a dull thud, a bolt a buzzy rattle. Cage's Sonatas and Interludes for prepared piano (1946–1948) is the masterwork of the medium — 20 pieces inspired by Indian aesthetic theory that require 45 carefully specified preparations. The notation looks like normal piano music, but the sounds are entirely transformed. The prepared piano has been adopted by many subsequent composers and improvisers. The concept expanded into prepared guitar, prepared harp, and other "prepared" instruments. Cage's innovation demonstrated that radical sonic transformation doesn't require new technology — just a new way of thinking about existing instruments.