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

each line in a polyphonic texture appears to go its own way, they all share the same
metre and harmonic structure, and each line is intimately related to its fellows.
Paradoxically, the illusion of independence is dependent upon this close relationship:
harmonic congruence gives each strand its own function within the chord, which
changes from moment to moment, just as the complementary rhythms between the
parts enable each voice to move in the others’ gaps. The relation between a fugal
subject and the rest of the texture operates along similar lines: the subject enters the
texture at various times, and, though recognisable as a thematic landmark, it does not
determine the texture and the phrase structure of the whole like a theme in a sonata
movement; it just happens to ‘fit’, as if through pure serendipity. This is of course
equally an illusion; if the subject does not completely determine the harmonic and
tonal course of the entry (as many nineteenth-century theorists thought), it obviously
exercises a strong influence, being itself fixed. If there is a regular counter-subject, the
subject determines the course of at least one other voice. Nevertheless, the fragile
illusion remains intact unless, as here, the subject repeats part of itself. Suddenly (and
repeatedly throughout the fugue) the implicit authority of the subject over the texture
becomes explicit as the other voices are brought rigidly into step with it. Although it
has a certain amount of (complementary) rhythmic independence, the counterpoint to
the subject presents no strong idea that might compete with the subject for interest; it
is, in short, an accompaniment to a tune. Significantly, apart from a single bass entry
during the exposition the subject appears only in the topmost voice—soprano or alto,
according on circumstances. It is quite long (there are only six complete entries), and
really sounds more like a self-contained melody with accompaniment. As in the other
fugues, there is a substantial quantity of homophonic writing, much of it in syncopated
parallel thirds and sixths. Taken individually, all of the material would be quite at
home in one of Friedemann’s or Emanuel’s sonata movements (compare, for example,
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