This study makes available in English translations the three most important theoretical writings of the Austrian composer Josef Matthias Hauer (1883—1959), whose experiments with atonal and dodecaphonic music are discussed in the treatises. The treatises are Vom Wesen des Musikalischen: Grundlagen der Zwolftonmusik, Vom Melos zur Pauke: eine Einfuhrung in die Zw51ftonmusik, and Zwftlftontechnik: die Lehre von den Tropen. In addition to the translations and commentary the dissertation includes a sketch of Hauer's career and an examination of his claim that he—not Arnold Schoenberg—was the inventor of the dodecaphonic school of composition.