This volume represents the proceedings of an international musicological colloquium held at Harvard in March 1979. The broad spectrum of papers and extensive scholarly debate focuses on a quintessential repertoire of musical works from the classical era. The autograph sketches, drafts, and scores of various kinds are shown to be central sources for our understanding of the genesis and history, as well as for the analysis and performance, of the compositions. Contributors are Lewis Lockwood, Laszlo Somfai, Jens Peter Larsen, James Webster, Georg Feder, Ludwig Finscher, Marius Flothuis, Alan Tyson, Christoph Wolff, Richard Kramer, Robert Winter, Sieghard Brandenburg, and Martin Staehelin, scholars working on the frontiers of current research in Haydn, Mozart, and Beethoven studies. An appendix provides chronological tables, a catalog of the extant autograph manuscripts, and an extensive bibliography.