The Art of Fugue
As in Contrapunctus III, Bach uses an inversion of the main AOF subject, but this time he starts it on the dominant rather than the tonic:
This puts the inversion firmly on the D minor triad, unlike the troubled wandering of the Contrapunctus III subject, and the result is a joyful transformation of the mood of that previous fugue. Here is Easter to Contrapunctus III’s Good Friday, a radiant burst of music that sets the stage for much of the rest of the cycle.
For the first time thus far in AOF, I use the full orchestra employed in this realization, including the great organ and the upright bass bumping happily along in the bass. This fugue is perhaps best experienced after hearing the first three, where its transformative affekt is most dramatically revealed. Either way, it’s a treasure, so sit back and enjoy!
A big part of the joyful character of this fugue is the little two-note motive that runs through it:
Does that look familiar? Right, it’s the augmentation of its pensive cousin from Contrapunctus I! Thus are the first and fourth fugues tightly linked, tying this set of four fugues nicely together.
Listen also to the first appearance in AOF of stretto — overlapped instances of the fugue subject. You’ll hear it twice, toward the end, at 2:25 in the tenor and bass, and again at 2:30 in the alto and soprano. Thus, in addition to looking back to Contrapunctus I, this fugue prepares the ear for the stretto fugues that begin in Contrapunctus V.
The subject also appears sixteen (4 x 4) times, perhaps an emphasis, at this conclusion of the first quartet of fugues, of the 4-symmetry of AOF.