MOZART AND THE PRACTICE OF SACRED MUSIC, 1781-91 a ...

and later added some of his own devising. The incomplete state of the manuscript and the
evident speed at which Mozart was copying speak against such deliberate modifications,
however. These conclusions are necessarily tentative, and further research on Mozart as a
scribal interpreter of other composers’ music is clearly required. 139
If the copy of Reutter’s Kyrie was not based on the Hofkapelle source, where did
Mozart gain access to the work? Hofer listed copies of the mass at Heiligenkreuz,
Herzogenburg, Göttweig and Eisenstadt, and I have identified two further sources: a lost set
of parts cited in the catalogue of St. Stephen’s Cathedral, 140 and a score copy of eighteenth-
century Viennese provenance from the King’s Music Library. 141 As I have emphasised, we
know very little about Mozart’s church-going in Vienna, and it is entirely possible that the
composer visited one of the city’s churches and copied the Reutter pieces from a source that
no longer survives. Did Mozart, manuscript paper in hand, visit a music archive and copy
the pieces there, or did he borrow them and copy them at home? We simply do not know.
Holl considered it certain that Mozart’s copying was prompted by a performance, and
thought it inconceivable that “ein Mann wie Mozart sich die Mühe gemacht hätte,
systematisch im Aufführungsmaterial der Hofkapelle oder irgendeiner Kirche nach
Kompositionen zu suchen, um dann aus über 80 Messen und 150 Psalmen von Reutter
gerade diese Stücke auszuwählen.” 142 It is however most unlikely that any church archive
would contain all of those 80 masses or 150 psalms, so the idea of Mozart searching through
the material for something of interest is less problematic than Holl suggests. Perhaps
139 On the Salzburg copies, see Cliff Eisen, “The Mozarts' Salzburg Music Library,” in Mozart Studies 2, ed.
Cliff Eisen (Oxford: Clarendon Press, 1997), 85-138.
140 A-Wda, s.s., 14. The parts, marked “NB”, were probably discarded in the late nineteenth century; see the
following chapter.
141 GB-Lbl, R.M.24.g.13.1. The same volume contains a Te Deum by Reutter in the hand of Edge’s Viennese
Mozart-Copyist 3. The watermark in both manuscripts is Tyson 78, suggesting a date in the mid-1780s. Just
how a Catholic mass came to be in the music library of the British royal family has yet to be explained.
142 Holl, “Nochmals: "Mozart Hat Kopiert!"”: 36.
177