Music of Changes is a piece for solo piano by John Cage. Composed in 1951 for pianist and friend David Tudor, it is Cage’s earliest fully indeterminate instrumental work.
Music of Changes was the second fully indeterminate work Cage composed (the first is Imaginary Landscape No. 4, completed in April 1951, and the third movement of Concerto for prepared piano also used chance), and the first instrumental work that uses chance throughout. He was still using magic square-like charts to introduce chance into composition, when, in early 1951, Christian Wolff presented Cage with a copy of the I Ching (Wolff’s father published a translation of the book at around the same time). This Chinese classic text is a symbol system used to identify order in chance events. For Cage it became a perfect tool to create chance-controlled compositions: he would “ask” the book questions about various aspects of the composition at hand, and use the answers to compose. In effect, the vast majority of pieces Cage completed after 1951 were created using the I Ching. [source]
Book I (New York, May 16, 1951)
Book II (New York, August 2, 1951)
Book III (New York, October 18, 1951)
Book IV (New York, December 13, 1951)