The Art of Fugue
Bach has introduced his main subject in two slightly different forms in Contrapunctus I and Contrapunctus II. Now he inverts the subject. Instead of the regular subject:
the fugue now begins with this:
This inverted subject appears first in the tenor, and then is answered in the alto at 0:12 by a new idea, a descending, chromatic countersubject (listen for it played by the organ, answering the subject in the strings):
Finally, Bach further enriches the mix by introducing a new, inverted variant of the main AOF subject:
(Listen for this one first appearing in the violins at 1:06.)
The moody subject, its even more melancholy countersubject, and the tension of the weak-beat variant of the subject, all appearing in strict inversion combine to create the darkest moment of AOF. Sighing chromatic figures call and answer throughout, as if voces clamantes in deserto. After the exposition, there is no subject entry in the bass voice until 2:29, and when it does come, it is a quiet snarl. The fugue then builds to an anguished chromatic climax at 3:08, after which the lines descend to the dead.
As you listen to this fugue, listen for this motive in the bass:
This idea will reappear in the similarly intense and chromatic Contrapunctus XI.
The first three fugues of AOF are decidely somber, and Bach concludes them with a clear motivic link to the other truly stern part of the cycle — Contrapunctus XI. It is as if, in the largest structure of AOF, Bach is employing the first three fugues as a prelude to the sparkling essays that will follow, while subtly noting that all will not always be roses.
Three is the number of the Trinity. Eleven, to which Three in AOF is gently linked, is the canon of BWV 1087 in which Bach explicitly notes a spiritual connection. In this third fugue of AOF’s first quartet, Bach presents the inverted subject twelve (3 x 4) times…and the main AOF subject (see the first graphic above) has 3 x 4 notes, by the way. Amusing coincidence, musical necessity, or embedded symbolism of 3, 4, 11, 14? Perhaps all three?