Williams Mix (1951–1953) is a 4'15" musique concrete composition by John Cage for eight simultaneously played independent quarter-inch magnetic tapes. The first octophonic music, the piece was created by Cage with the assistance of Earle Brown, Morton Feldman, and David Tudor, using many tape sound sources and a paper score he created for the construction. "Presignifying the development of algorithmic composition, granular synthesis and sound diffusion," it was the third of five pieces completed in the Project for Music for Magnetic Tape (1951–1954), funded by dedicatee architect Paul Williams Jr.