one of the leading American composers of avant-garde music, best known for his development of graphic notation and the open-form system of composition.

Brown had been trained in engineering and mathematics before he began to study music theory and composition. In the early 1950s he met the experimental composer John Cage (Cage, John), who strongly influenced Brown's music. In 1952 Brown developed a system of graphic notation, the use of nontraditional notational syllables across a writing surface in such a way that they are analogous to the passage of music through time. In 1953 he further put forth an open-form technique of composition, such that the conductor or performer determines the sequence of a group of musical units. Brown's first open-form composition, Twenty-five Pages (1953) for 1–25 pianists, has a score of 25 pages that are to be arranged in a sequence chosen by the performer(s). Most of Brown's later work further developed graphic notation and open form.