Final answer:
John Cage composed the Sonatas and Interludes for prepared piano between 1946 and 1948, fundamentally changing the piano's sound and challenging traditional music conventions.
Step-by-step explanation:
The Sonatas and Interludes for prepared piano were composed by American avant-garde composer John Cage between 1946 and 1948. This innovative work represented a radical departure from conventional piano composition and performance, involving the alteration of the piano's sound through the placement of various objects between or on the strings, which Cage specified in great detail. These objects included bolts, screws, rubber, pieces of felt, and plastic, creating a completely new set of sounds that were reminiscent of percussion instruments, much different from the traditional timbre of the piano.
The impact of Cage's work extends beyond the music itself and into the philosophy of music, challenging audiences to reconsider what music is and exploring the idea of organized sound. His use of the prepared piano has inspired a wide array of experimental musicians and remains a significant piece of modern music history.