The Missa Sti Bernardi von Offida (1796) stands at the beginning of Joseph Haydn’s late works. The Mass earned its nickname because in the Sanctus Haydn quoted the then well-known sacred hymn “Heilig, heilig, heilig.” The text of the music for this critical edition presents the work with the complete scoring for winds, including the clarinets and horns missing in the autograph score and the first edition. The optional horn parts are contained in the appendix and as part of the performance material. However, these parts cannot be dispensed with if we wish to fully re-create the Mass within the context of Eisenstadt.