Jan. 17, 2018
(con't from Part XXIX)
When we first contemplate composing a new prelude and fugue, it's usually easier and more productive of our time to create the fugue first, then go back and work a prelude to go with it.
A solid, well crafted fugue can be created in just a matter of days using the method described on this web site [See blog, Ten Steps].
One of the first decisions to be made is whether or not the prelude will be related to the fugue in terms of its thematic material.
If the prelude is to be related, and if the fugue has 2 countersubjects which are maintained throughout, then this could suggest a 3-part form for constructing the prelude using the fugue's 2 countersubjects to build it.
This procedure is illustrated in the score of the e minor Prelude & Fugue Op. 24 (photo); it will be instructive to download and print a hard copy of this score and suggestions for performance as this narrative proceeds.
If the Fugue is already finished we know that both countersubjects combine with each other, thus the Prelude can be constructed of 3 thirds, the first 2 thirds of which introduce each countersubject separately with the final section being combinatory.
The countersubjects may be extended to, shall we say, 7 bars in length each, and harmonized in 4 parts; these 7 bar sections are to follow each other and be separated by a short modulating interludes of 3 bars each; a short introduction of 2 bars and coda of 3 bars would be sufficient to round off the piece.
We would then have a very compact, useful prelude of 32 bars length that could take a relatively short time to compose and would give the illusion that it was created first when in the real world of composing it was just the other way around.
Here the finished Fugue donates material to the Prelude which, like a seed, contains an invisible instruction on what to become (photo); the illusion is that the Fugue seems to grow out of what's in the Prelude after the Prelude runs its course.
In this work the Fugue was written in 3 days and the Prelude took 2 days, thus all of 5 days were occupied in its creation.
The applications of the method used to construct fugues in 10 progressive steps [See blog, Ten Steps] have been discussed in previous blog postings and need not be repeated here except to give some general remarks:
By way of review, we have to start with a subject that lends itself to contrapuntal elaboration, and by that we mean "workable," not necessarily ear catching or even tuneful; it has to lend itself to fugal procedure.
That subject has programmed within its cells the growth of the entire fugue.
The subject of this Fugue, from Op. 24, begins on the 1st scale degree, is 5 bars long, and its tail points strongly to the dominant; this means that there need not be a tonal answer; a real answer (literal transposition of the subject, note for note) may be supplied in the dominant on the 5th scale degree [See blog, Getting Started With Writing, Part XX].
The opening entry is in the tenor line and is answered in the soprano as the tenor continues with the 1st countersubject in the dominant; a short modulating passage of 2 bars provides a smooth return to the home key for the 3rd entry which is in the alto; here the soprano continues with the 1st countersubject as the tenor continues with the 2nd countersubject; this is followed by the 4th entry in the bass in the dominant with a free voice filling in the tenor line, all as expected.
This Fugue continues with 5 more entries in 4 voices and in all nearly related keys (G Major, a minor, D Major, C Major, E minor) separated with regularity by 2 voice modulating episodes each 4 bars long written for inner voices only (alto and tenor).
The subject and countersubjects are "tweaked" slightly in these entries to get them to work better in vertical harmony with all the other moving lines and to keep voice lines from crossing; this also provides a bit of variety and helps keep the listener interested [See blog, Tweaking].
How this tweaking was done will repay careful study.
The 2 voice modulating episodes between expositions were constructed primarily of sequences based upon the inverse of the head of the subject and countersubjects [See blog, Sequencing, Inversions].
Following many examples set by J.S. Bach the final entry in the home key (e minor) is in the bottom octave of the pedals with an increase in loudness; a finishing coda of 3 bars with the full power of the organ rounds out the work with the addition of a 5th voice, 32-foot tone in the bass, and a ritardando; the final chord ends with great finality and the full power of the instrument employing a Picardy 3rd which is preceded by a trill in the top line.
When performed with the right tempos, stops, and use of the swell, this Fugue will conclude with great grandeur and impressiveness.
The paired Prelude takes its thematic material from the 2 countersubjects in the Fugue; this creates a compact yet interesting piece in 3-part form thematically related to the Fugue.
The 1st section of the Prelude in the home key (e minor) is built upon the Fugue's 1st countersubject which enters in the soprano line and is harmonized in 4 parts following a short introduction of 2 bars (both countersubjects, being only 5 bars long, were extended in this Prelude to 7 bars each).
The introduction consists of a tonic pedal point on low E over which the tenor enters with an outline of the Fugue's subject rhythmically transformed to a series of running 8th notes which is repeated in imitation in the 2nd bar in the alto.
The means here for creating an introduction are simple and don't have to be long winded or complicated; when deciding between a longer or shorter version of an introduction or coda, the shorter one generally works out best; the result here is an opening which establishes the tonic key, grabs the listener's interest, and gives the sense that the Fugue's subject, when it enters later on, emerged from the opening of the Prelude when it was exactly the other way around.
This 1st section is followed by a modulating interlude 3 bars long which ends in the related key (G Major) where the 2nd countersubject then enters in the soprano and is harmonized in 4 parts.
Another modulating interlude of 3 bars with a return to the home key connects this 2nd section with the 3rd and final (combinatory) section.
In this final section the 1st countersubject enters in the tenor and the 2nd countersubject in the soprano as 2 other free voices fill in the harmony in the alto and bass; this part of the work concludes with a full cadence in 5 voices with the final tonic chord in e minor preceded by a trill in the top line.
The Prelude therefore succeeds in introducing the Fugue's countersubjects to the ear this way such that, when the Fugue opens, there is this impression of familiarity already with 2 of the 4 moving lines in the Fugue, creating a very strong sense of unity.
This work is an example of how a new and useful prelude and fugue can be created in just 5 days, almost as if by magic, using a proven 10 step method, some appropriate thematic materials, having an idea for building a prelude after the fugue portion is completed, and just setting aside fear and having the guts to try [See blog, The Book].
(con't in Part XXXI)