The German composer Karlheinz Stockhausen was arguably the most influential figure of the European postwar avant-garde, and unquestionably the most elusive and enigmatic musical thinker of a generation that includes Pierre Boulez, John Cage, and Luciano Berio. His radically new electronic and instrumental music converted Igor Stravinsky to serialism in the 1950s, and has continued to inspire young composers for over fifty years. This present volume draws on over forty years of the author's close study of Stockhausen and functions as a catalogue raisonee of Stockhausen's complete output. With plentiful citations from the history of radio, film, and sound recording, as well as from contemporary science and technology, the book is laid out in strictly chronological order and contains unusually ample commentary on the composer's sources of inspiration. Each composition is also fully documented within the text, giving full information of each work's publisher, catalogue number, instrumentation, duration, and authorized compact disc. Any listener will benefit from this work and American music lovers in particular will find it an invaluable guide to the ongoing debate and rivalry over the sources of abstract expressionism and the avant-garde.