In the years from 1908 to 1923, Arnold Schoenberg developed a compositional strategy that moved beyond the accepted concepts and practices of Western tonality. Pieces form this period such as Pierrot Lunaire and Erwartung remain masterpieces of the modern repertoire. The lasting importance of Schoenberg's atonal music is reflected in the very large but fragmented critical and analytical literature that surrounds it. In this book, Bryan R. Simms synthesizes and advances the state of knowledge about this body of work, building up a comprehensive description from close analytical study.