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

As he says, although subjects outlining the diminished seventh had been common
since the time of Frescobaldi, subjects that place this interval between the third and the
sharpened fourth degree are much rarer, and otherwise unknown in Bach.
Equally peculiar are two points not mentioned by Humphreys. First of all, this
shift to the dominant is rather unusually cancelled by an immediate descent to the
tonic; secondly, the final note of the subject is an octave lower than the opening.
Although their total range may considerably exceed Mattheson’s octave rule of thumb,
Bach’s fugue themes almost always return to their opening tonic, or the third or the
fifth. The precipitate descent of BWV 534’s subject contrasts strongly with the
centralised, self-contained movement of most Bach fugue subjects.
To an extent these factors tell (if not conclusively) against the work’s
authenticity. Are these stylistic distinguishing marks also aesthetic considerations?
The unexpected leap to the sharp 4th is a little more abrupt than Bach’s usual practice,
and its immediate cancellation perhaps vaguely unsatisfying, but these aspects are
probably better thought of in terms of expectations fulfilled or denied—distinctive
characteristics—than as qualities or defects. Of more concern is the subject’s rapid
octave descent. This does not immediately impair the beauty of the line, but it does
have implications for the subject’s workability in a fugal texture. Whenever it appears
in the tenor, its descent tends to result in a bottom-heavy texture; in an upper voice, it
frequently has to cross below the voices underneath. In either case, the fact that the
subject ends in a register other than that in which it started tends to obscure thematic
and textural clarity.
Once the contrapuntal texture builds up, harmonic infelicities accumulate to a
level it is difficult to avoid noticing—if one is looking for them, that is. Examples that
are difficult to interpret other than as flaws include the nasty clash in b.11, unexplained
second inversion chords in bb.13 and 20, the poorly directed alto line in bb.9-13, the
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