Music of Changes

Music of Changes is a piece for solo piano by John Cage. Composed in 1951 for pianist and friend David Tudor, it is a ground-breaking piece of indeterminate music. The process of composition involved applying decisions made using the I Ching, a Chinese classic text that is commonly used as a divination system. The I Ching was applied to large charts of sounds, durations, dynamics, tempo and densities.

Music of Changes was the second work Cage composed to be fully indeterminate in some sense (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. The vast majority of pieces Cage completed after 1951 were created using the I Ching.

The title of Music of Changes is derived from the title sometimes given to the I Ching, "Book of Changes." Cage set to work on the piece almost immediately after receiving the book. The dates of composition are as follows: Book I completed on May 16, Book II on August 2, Book III on October 18 and Book IV on December 13. Cage's former mentor Henry Cowell remarked that Cage had not freed himself from his tastes in the new work, and so for a short while Cage worked simultaneously on Music of Changes and Imaginary Landscape No. 4, which was to do what Cowell suggested.

...
Wikipedia