Getting Started With Writing, Part XXXVI

(con't from Part XXXV)
"The great J. Seb. Bach used to say 'Everything must be possible,' and he would never hear of anything being not feasible. This has always spurred me onward to accomplish many difficult things in music, by dint of effort and patience, according to my own poor powers."
-- Johann Kirnberger, pupil of J.S. Bach

We've seen a number of successful 4 voice organ fugues using the Ten Step method for fugue writing described on this blog [See blog, Ten Steps].
We've learned, among other things, that what theorists may be teaching and maintaining about fugue writing, as far as it goes, doesn't always apply in every application.
We've demonstrated, for example, that a correct organ fugue can have a subject which starts on the 3rd scale degree provided its subject has a tail which points strongly to the dominant key and is followed by a tonal answer [See Getting Started With Writing, Part XXXVII].
Since both the F Major Fugues from Op. 19 and 27 were written in triple counterpoint employing 2 countersubjects we might examine other examples having 3 countersubjects written in quadruple counterpoint employing 3 countersubjects, which includes entries in all related keys and perhaps one unrelated key.
In this connection the scores for the Op. 29 and 30 Postlude will be instructive.
As the famous 19th century French organist Camille Saint-Saens aptly pointed out, "The fugue is the ideal form for the postlude; as the voices enter, the people leave; when all the voices have entered, all the people have left."
With this observation in mind the Op. 22, 29, 30, and 31 stand alone fugues were given the simple title "Postlude."
In the Op. 29 Postlude in e minor (photo) the subject begins on the 3rd scale degree in the tenor voice and is provided with a tonal answer in the soprano; the exposition continues with the 3rd entry in the alto and the 4th entry in the bass to complete a 4 voice texture.
Since the subject and its 3 countersubjects are relatively long (5 bars), sixteenth rests were included to break the subject and countersubjects into smaller phrases to give them room to breathe and make them sound more "singable."
Like so many other fugues, the 2nd entry in this exposition is followed by a codetta (link) of 2 bars whose function is to prepare a smooth 3rd entry in the tonic key.
Each of the succeeding entries are separated by episodes of 5 bars length, each of which are constructed around the subject or one of the countersubjects in inverted or retrograde form.
This score, like the d minor Op. 22 Postlude, is marked at certain places when something else (the bass line) enters to remind performers where the tempo is to slow very slightly, then resume, to create nuance and keep the listener with them; this also keeps the music elastic, living, and breathing; a fugue, like any other piece of organ music, should never be performed mechanically and predictably with every move it makes, as though a typewriter was playing, page after page, in an unvarying tempo from first note to last.
The episode following the exposition modulates to a G Major entry where the subject enters in the soprano, the 1st countersubject in the alto, the 2nd countersubject in the tenor, and the 3rd countersubject in the bass.
Another modulating episode brings the music to an entry in b minor where the subject enters in the alto, the 1st countersubject in the tenor, the 2nd countersubject in the bass, and the 3rd countersubject in the soprano.
In the following entry in D Major the subject enters in the bass, the 1st contersubject in the tenor, the 2nd countersubject in the alto, and the 3rd, once again, in the soprano.
So far, these have all been related keys, but an episode follows which lands the music in the unrelated key of g minor where the subject enters in the tenor, the 1st countersubject in the alto, the 2nd countersubject in the soprano, and the 3rd in the bass.
From there the music modulates to C Major where the subject enters in the alto, the 1st countersubject in the bass, the 2nd countersubject in the tenor, and the 3rd in the soprano.
With this entry all 4 moving lines have entered at least once in the bass, thus establishing quadruple counterpoint.
The ensuing entry in a minor has the subject entering in the alto, the 1st countersubject in the tenor, the 2nd countersubject in the soprano, and the 3rd in the bass.
A section of 8 bars follows in which the head of the subject is inverted and enters successively in the tenor, alto, and soprano lines in imitation at the interval of 2 bars as the music undergoes a crescendo.
This brings about a return to the home key (e minor) during which the subject, following many examples by J.S. Bach, enters in the bottom octave of the pedals; here the 1st countersubject enters in the alto, the 2nd countersubject in the soprano, and the 3rd in the tenor.
The work concludes with a short coda of 4 bars during which a 5th voice (low tenor, or baritone) is added to the middle staff as the music undergoes a further crescendo.
The music finishes with great finality in 6 voices employing a Picardy 3rd on the final chord following a trill in the top voice and an anticipation on the tonic note.
How this work was constructed will repay careful study.
(con't in Part XXXVII)