The first edition of the musical works of E.T.A. Hoffmann, begun in the 1920s, foundered as a result of adverse economical conditions and because it was an enterprise ahead of its time. In the intervening years the E.T.A. Hoffmann specialist Friedrich Schnapp has rediscovered several works previously unknown or believed lost, his close collaborator Gerhard Allroggen documented the musical œuvre of Hoffmann bibliographically in a ‚Chronological Thematical Catalogue‘ . The present edition is based on this preparatory research and presents more than half of E.T.A. Hoffmann‘s musical works in a critical edition of 12 volumes. Most of the works omitted consist of his numerous stage compositions. But apart from his main dramatic work ‚Undine‘- published here for the first time in its original form - this section also contains ‚Die lustigen Musikanten‘ (a particularly successful setting of Brentano‘s musical comedy), ‚Liebe und Eifersucht‘ and his first work ‚Die Maske‘ (1799), the only surviving large-scale dramatic work where Hoffmann himself adapted the libretto. The incidental music for Zacharias Werner’s ‚Kreuz an der Ostsee‘ is interesting because of the notoriety achieved by the play. ‚Arlequin‘ is representative of Hoffmann‘s ballet music. Hoffmann‘s work in other genres, including sacred music, orchestral works, piano and chamber music, choral pieces, arias and lieder, are all published complete. In contrast to the stage works, they are much smaller, and their general importance as well as their use for practical music making are increasingly recognized. Each music volume contains a preface with the genesis and description of each work as well as a Critical Commentary listing the sources and necessary textual emendations.