In the United States, electronic music was being created as early as 1939, when John Cage published Imaginary Landscape, No. 1, for two variable-speed turntables, frequency recordings, muted piano, and cymbal. Cage composed four more "Imaginary Landscapes" between 1942 and 1952, all of which included electronic components. In 1951, Morton Feldman, who would later collaborate with Cage, produced a piece titled Marginal Intersection, scored for winds, brass, percussion, strings, 2 oscillators, and sound effects of riveting, and the score uses Feldman's graph notation.
The Music for Magnetic Tape Project was formed by members of the New York School (John Cage, Earle Brown, Christian Wolff, David Tudor, and Morton Feldman), and lasted three years until 1954. Cage wrote of this collaboration: "In this social darkness, therefore, the work of Earle Brown, Morton Feldman, and Christian Wolff continues to present a brilliant light, for the reason that at the several points of notation, performance, and audition, action is provocative.
Cage completed Williams Mix in 1953 while working with the Music for Magnetic Tape Project. The group had no permanent facility, and had to rely on borrowed time in commercial sound studios, including the studio of Louis and Bebe Barron.