The first page of the autograph of the Mass K.49 (47d) bears below the author’s name the crossed-out (autograph?) suffix “in Wien” (“in Vienna”).  “1768” and “in Wien” have been added by two other unidentified, eighteenth-century hands.  Mozart’s handwriting and the paper quality appear to verify this information.  Moreover, Mozart sketched the draft of the Gloria (measures 1 to 18) on a piece of paper, the reverse side of which his father had used, undoubtedly before that, for the fair copy of the piano score of aria no. 11 from Bastien et Bastienne K. 50 (46).  In Leopold Mozart’s list of works composed by Wolfgang up to 1768, “Eine kleinere Messe a 4 vocibus 2 Violinis &c” (“a small Mass with 4 voices, 2 violins, etc.”) appears as the penultimate entry; the year 1768 was added by Mozart’s sister.  Although the obbligato viola is not mentioned there, this comnposition is surely the Mass K.49.<br>