The iotaCenter, a Los Angeles-based organization for the preservation and promotion of abstract film, has produced this two-part series celebrating the often neglected work of the San Francisco Beat filmmakers. At the center of this movement was Hy Hirsh (1911–1961), a significant presence in avant-garde filmmaking of the 1950s who is little remembered today. Working as a cinematographer and still photographer in Hollywood during the 1930s, Hirsh pioneered the use of oscilloscope patterns as a source for abstract figures, which he then colored and multiplied with his own hand-built optical printer. His scores were often a mixture of street sounds and experimental jazz he recorded himself. Mentor to a generation of experimental makers, he taught filmmaking and loaned equipment to young artists, including James Broughton, Sidney Peterson, Jordan Belson, and Harry Smith. All of Hirsh’s films were impounded by the French police after his death in Paris. Many of the originals were lost, and most of the films have been unavailable for decades.