Over his long career, German composer Karlheinz Stockhausen relentlessly pushed post-war classical music in radical new directions. Debuting as a serialist, Stockhausen quickly became known for his pioneering electronic works of the late '50s and early '60s. In the decades that followed, Stockhausen often mixed electronics into his orchestral and choral compositions—perhaps most notably in the series of seven operas he composed between 1977 and 2003. While always rigorously conceptual, Stockhausen's greatest music hits the listener as an overwhelming rush of otherworldly sound.