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

to enclose your letter to me?’ 35 It is quite likely that this piece was written and sent
with much the same intention. Clavier sonatas were general-purpose music, of use to
amateurs at home, professionals in public, 36 and teachers in the studio. Preludes and
fugues on the other hand were specifically the province of clavier virtuosi, a means of
showing off both their facility in improvisation (or at least an improvisatory manner)
and their contrapuntal learning. It seems Nannerl lacked the training or the knack for
improvisation, and on several occasions her brother supplied her with written-out
preludes intended to sound improvised (cf letters, 11 October 1777, 20 July 1778;
K.15g, K.284a, K.395/300g, K.626aII/I). 37 Next to the great C minor fantasia K.475 it
is the largest and most ambitious of Mozart’s free preludes. It may be that the gift of
this piece is a quite specific reference to the lost intimacy of their days as child
virtuosi. Into the recollection of this shared experience, which no one else—not even
Leopold—could really share, Wolfgang introduces the person of Constanze, as the real
origin of the piece in question.
To what extent was Constanze her husband’s muse? The year of their marriage
saw a flood of projects initiated in her name: the fugues mentioned in this letter, a
series of violin/clavier sonatas for ‘ma trés chére Epouse’, movements for two clavier,
assorted vocal pieces, and of course the great mass in C minor. 38 Yet of all these
intended works, only this prelude and fugue was ever completed—by Mozart himself,
at least: ‘One after another, he wrote a quarter, half, three quarters of a fugue; all of
them break off, as if he was reluctant to satisfy Constanze fully.’ 39 It is all too
35 Anderson, Mozart letters, vol. III, p.1193.
36 Unlike concertos, solo sonatas seem to have played a relatively small part in commercial public
concerts (Salomon’s series, for example), but they had a significant role in the semi-public soirées at
the houses of the nobility which formed such a large part of Mozart’s professional life.
37 The extent to which deceit was intended is not clear; as late as 1823 Adolph Marx was surprised to
come across the ‘improvisation’ with which Friedrich Kalkbrenner had recently impressed him in
print as a Grande fantasie ‘Effusio musica’, op.68; see H. C. Schonberg, The great pianists (London:
Gollancz, 1963), p.111.
38 The B flat Allegro K.400 could also be numbered with these, as Constanze and her sister Sophie are
named on the autograph.
39 Hildesheimer, Mozart, p.246.
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