Since his death in 1935, Heinrich Schenker's influence on music theory has steadily increased. This indexed guide to an archive of Schenker's manuscripts is augmented by the Nachlass of his pupil Jonas and his close friend Violin. The catalog describes each manuscript and provides access to Schenker's critical works, his annotated scores and performance comments, his correspondence with Furtwängler, Schoenberg, and others, and his diaries (1896-1935). The Jonas collection is at the University of California, Riverside.