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

Equally notable are passages which, while not fugal or imitative, have a weight
and monumentality clearly derived from the example of Bach and Handel; notably the
‘gratias agimus’ and ‘Jesu Christe’ from the Gloria. Most impressive, however, is the
‘qui tollis’. The other two passages are episodes, twelve and six bars long
respectively; the ‘qui tollis’ continues, Largo, without a break, for no fewer than fifty-
six bars. The orchestra maintains a double-dotted accompanimental pattern
throughout, while two four-part choirs alternate and combine over this background.
As with many of the Bach preludes from the WTC (which Mozart would have come to
know at van Swieten’s) the chief mode of musical progression is harmonic rather than
thematic.
What inspired the eight-part texture? One thinks immediately of Bach’s motet
‘Singet dem Herrn’, which we know Mozart came across in Leipzig; but this was in
1789, seven years later. Did Mozart know of the double choruses to be found in
certain oratorios of Handel, notably Israel in Egypt and Solomon? There was also a
native Viennese tradition of polychoral liturgical music, going back to the time of
Johann Heinrich Schmeltzer. Mozart’s Salzburg predecessors, Eberlin, Adlgasser, and
Michael Haydn, all produced occasional works for double choir. Perhaps there is no
single source, but a generalised awareness of expanded choral textures as being a part
of the style of the ‘old masters’ he was seeking to emulate, coupled with a desire for
textural weight and density. Along with the ‘qui tollis’, the ‘Sanctus’ and ‘Osanna’ are
in eight parts, the ‘gratias agimus’ and first part of the Credo in five (SSATB). Mozart
shows no more concern for consistency in the division of voices than did J. S. Bach in
his B minor mass.
With the Sanctus and Benedictus we come across a new problem. Not only did
Mozart leave the mass incomplete, but even some of what he did finish has been
preserved in a very imperfect form. Missing from what is left of Mozart’s autograph
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