John Cage (born September 5, 1912, in Los Angeles, California, USA; died August 12, 1992, in New York City, New York, USA) was a prominent American composer, music theorist, writer, philosopher, and artist, recognized as a pioneering figure in post-war avant-garde music.

Cage began his musical journey at Pomona College but left early to explore Europe from 1930 to 1931. He continued his studies in New York with Henry Cowell from 1933 to 1934, and then with Arnold Schoenberg in Los Angeles in 1934. It was during this period that he composed his first published works, characterized by a rigorous atonal system of his own design. In 1937, he relocated to Seattle to serve as a dance accompanist, and in 1938, he established a percussion orchestra. His compositions began to focus on filling time units with ostinatos, exemplified by his work First Construction in Metal (1939). Cage also ventured into electronic music, utilizing variable-speed turntables in Imaginary Landscape No. 1 (1939), and he invented the 'prepared piano,' a technique that involves placing various objects between the strings of a grand piano to create a unique percussion ensemble.

Cage's artistic journey took him to San Francisco in 1939, Chicago in 1941, and back to New York in 1942, where he continued to compose music for dance companies, notably collaborating with Merce Cunningham, with whom he maintained a lifelong relationship. His innovative works during this time included major concert pieces for prepared piano and percussion ensemble, such as A Book of Music (1944) and Three Dances (1945) for two prepared pianos, as well as Sonatas and Interludes (1948) for one prepared piano. During this period, Cage also developed an interest in Eastern philosophies, particularly Zen.

Cage sought to eliminate personal choice from the creative process, employing coin tosses to determine the structure of his compositions, as seen in Music of Changes for piano (1951). He experimented with unconventional methods, such as writing for twelve radios in Imaginary Landscape No. 4 (also 1951) and introduced various indeterminate techniques. His iconic work 4'33" (1952) consists of no composed sound, only the ambient noise of the environment during its performance. The Concert for Piano and Orchestra (1958) serves as a comprehensive exploration of indeterminate notation. His later works reflected his growing interest in the theatrical aspects of musical performance, as demonstrated in Water Music (1952), which involved a pianist using an array of non-standard equipment, and in electronic compositions like Imaginary Landscape No. 5 (1952) and Cartridge Music (1960). His ambitious project HPSCHD (1969) exemplified his vision of large-scale events characterized by randomness. Cage's later output varied widely, including indeterminate pieces, fully notated works within limited material, and compositions involving natural resources, such as plants and shells.

Cage was a prominent figure in both Europe and the USA, widely recognized as a lecturer and performer, and he had a significant influence on younger musicians and artists.

He was married to Xenia Cage from 1935 until their divorce in 1945.