“Missa brevis in F in score. This was the first Mass which Mr. Haydn composed whilst still a student”, says an entry in the catalogue of Haydn’s musical estate. Circa 1798/99 Haydn entered the work without an incipit in his working catalogue as “Missa brevis in F. / a due Soprani”. Around 1805/06 he added in shaky, decrepit handwriting to the title “Missa.” on the front page of the organ part of one of the set of parts prepared by his copyist Johann Elßler: “Brevis / di me Giuseppe Haydn mpria /...