J. S. BACH Jonathan Berkahn - Victoria University - Victoria ...

come as no surprise, however, that the ‘cum Sancto Spiritu’ fugue is unusually long
and ambitious—perhaps the largest choral fugue he had yet written. For all the
supposed influence of van Swieten’s circle, however, there is very little of either Bach
or Handel to be found in it. The subject appears to be taken straight from Fux (the
Gradus ad Parnassum that is, rather than his actual choral works), but even he did not
as a rule use such lengthy, undifferentiated subjects as this (Ex.4.13):
As if made almost on purpose to invite Marpurg’s censure: ‘A long series of
plain, unaccompanied tones in a slow tempo [as a fugue subject] becomes unbearable
for the ear’, 69 it was not typical of the church music Mozart had written in Salzburg.
Now, however, with the space to expand into a really generously proportioned
movement, this sort of subject provides an excellent underpinning for the much
quicker counterpoint in crotchets and quavers that is to follow. There is perhaps a
reminder of Eberlin’s style in the rosalias in bb.67-73, 100-106, 134-38, and 178-184.
Unlike those in K.401/375e, however, these do not draw attention to themselves by
venturing outside the normal range of keys, and they are surrounded by other, freer
kinds of sequence and motivic development. In contrast to J. S. Bach’s usual practice
there is no regular countersubject. Instead Mozart employs a motive consisting of
three upbeat crotchets followed by a turn in quavers to serve a similar purpose. The
turn remains the same, but the three crochets appear in a variety of configurations:
69 A. Mann, The study of fugue (New York: Norton, 1965), p.162.
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