Happy Thanksgivings for all of you!
Here's a quote from the text written about Bach's fugue. Please comment if you find it grammatically correct or not (my English is pretty poor in this field)
The nucleus of the fugue's subject (downward fifth) is doubled at the
octave, creating an orchestral sound. The structure of the fugue is
completely different from that of the Fugue in A minor, BWV 947. There are
no additional elaborations in the exposition, which is followed by an
expanded development and a coda. The tonal plan is: a - C - e - g - F - a.
The fugue is relatively homogeneous; all answers (except the answer in E
minor at the "golden mean") have two suspended counter-subjects. In the
middle section, the subject is stated and answered in the aforementioned key
sequence. The episodes bring some variety, particularly the vivid
10-measure episode that begins at measure 37. This episode has a
homophonic, rather than polyphonic, structure. A brief version is presented
before the recapitulation. In the recapitulation (section III), the subject
is stated -- first in the bass and then in the tenor. Suddenly everything
"flows" into the prelude section; then a "proper" polyphonic coda resumes
for some time, ending in a dissonant sequence; and then... a concerto
begins. The fugue's subject is transformed, doubled at the octave in both
hands. Just like the beginning of the Alessandro Marcello Concerto edited
by Bach!