Complex counterpoint in Bach
July 31, 2018
Some of the most complex wonders of Bach’s counterpoint, such as the F minor Sinfonia or the first movement of the B minor flute sonata, result from a procedure that is structurally, surprisingly simple.
There are three voices in the Sinfonia and three in the flute sonata (two in the keyboard and one in the flute). At the same time, there are several distinct motives present, any one of which can appear in one voice or another at any time. There are often three different motives appearing simultaneously in the three voices.
This suggests a creative procedure similar to making a mosaic. In a mosaic, there may be only several differently shaped pieces, or tesserae. From these few pieces, the entire structure of the work is created.
Though there is great variety in the sound of the piece, the parts making it up at any one moment are just one of the severally shaped pieces of the mosaic.
The counterpoint is most effective when these basic pieces are as different from each other as is possible. The F Minor Sinfonia is the perfect example of this. There are just three motives: one is a series of slow, chromatically descending quarter notes; the second is a series of three eighth notes, a movement up of a third and then down of a second; the last is faster, moving motive in sixteenths and thirty seconds. Bach creates an entire universe, aesthetically full and complete, with these three motives that each take up abode in one voice and then another. What genius!
While artists may follow the procedure of “separating” the voices in their playing, sometimes the greatest separation effect comes from following a single motive as it migrates from voice to another. I first discovered this principle in the five voice fugue in C-sharp minor in Book One, especially after the eighth notes begin.