This extensive work is the culmination of more than a dozen years of research concerning Thompson's manuscripts, printed editions, lost compositions, and works that he was asked to write but did not. In compiling the catalogue, its authors personally examined all the evidence found in Thompson's own extensive Nachlass at Harvard University's Houghton Library, the bulk of which remains uncatalogued. The authors were also privileged to be given access to the E.C. Schirmer archive through the generosity of then-owner Robert Schuneman, and to numerous other private and public collections. Thompson's works, presented chronologically and given RT numbers, are described based on information gleaned from correspondence, diaries, personal interviews with his family, friends, and colleagues, newspaper reviews, the composer's own program notes, recordings, and assorted other sources. Extensive performance histories of the more important works are provided, and every known performance which Thompson himself conducted or attended is cited. In addition, conductors who particularly championed Thompson's works are given emphasis in the commentary and lists of performances. The authors' study has uncovered significant details about the compositional genesis and publishing history of works known to be part of the Thompson canon. As such, this catalogue will function as a sourcebook for future Thompson research and as a guide to locating materials related to the composer, particularly those at Harvard University.