In the beginning, when we're selecting new repertoire to learn, as soon as we're ready, it's a good idea to pick out, among other things, a fun, rhythmic piece of some kind, such as a "jig" fugue.
These brisk works in compound duple (6/8) time are not only instructional and good for the hands and feet but also good crowd pleasers.
They generally have tremendous audience appeal and make excellent postludes for feast days and encores for recitals.
As soon as we can, we should also try to write for ourselves.
A suitable subject can sometimes be arrived at by rhythmic transformation (same sequence of pitches, different note values) of the theme or subject from another work.
Generally, if we fashion a theme by starting with slower note values, then make the notes move a little faster at the tail end, this type of theme lends itself well to being a fugue subject and to fugal procedure; a classic example is the subject from the Art of Fugue by J.S. Bach; the theme, or subject, for this work does nothing but outline the tonic chord in slow notes, then picks up a little speed, and has a short tail in quicker notes -- it's very plain, almost without light, but it had tremendous workability in his hands, as he plainly demonstrated.
In the case of writing a "jig" fugue, we''re generally looking for a tuneful, quick-moving subject well supplied with disjunct motion (melodic movement by leap rather than step).
Having a countersubject for it is a good idea, and the notes in the countersubject should move whenever notes in the subject are stationary to keep everything constantly moving.
By introducing syncopations in the countersubject it will also lend additional interest.
We don't need to invert our theme or write it in inverse movement [See blog, Inversions] unless we want to ... we can keep it right side up throughout, just take it through various related keys.
The order of keys in the various entries which follow the exposition should be worked out in advance and proceed through most, if not all, (5) related keys, with an additional unrelated key or two included, if desired.
It would be good to maintain 4 voice harmony throughout with a reduction to 2 or 3 voices during each of the episodes; we might also keep the episodes curtailed (4-10 measures each) using motives derived from fragments of the subject or countersubect; the episodes do not have to maintain the same length throughout.
For the close we might present the subject and its countersubject over a tonic pedal point, perhaps working just the faster notes from the tail of the theme into the final measures.
This was the general plan used for Fugue a la gigue in D Major Op. 6 (photo), whose subject was derived by rhythmic transformation of the cantus firmus (c.f.) from the C Major Variations Op. 4.
It will help to download and print a hard copy of this D Major "jig" Fugue Op. 6 for 2 hands and follow this narrative on how it was put together, being particularly careful to observe what happens to the subject as it makes its various entries [See blog, Tweaking].
This "jig" Fugue is in 4 voices with 2 countersubjects.
The subject in compound duple time (6/8) enters first in the tenor in the home key on the 1st scale degree, thus is supplied with a real answer in the dominant in the alto; the tenor meanwhile carries the 1st countersubject.
The upward leap of a major 6th interval in the subject, having been derived from the c.f. of Variations Op. 4 and retained, this large leap in the subject requires it to be tweaked in several places in order to have room to squeeze it into the available vertical space, as this music is written on 2 staves only.
After 2 measures which gets the music back to the home key the subject makes a 3rd entry in the soprano, the alto carries the 1st countersubject, and the tenor carries a 3rd line which, since it's repeated throughout the Fugue, becomes the 2nd countersubject.
After 2 more measures the subject makes its 4th entry in the bass, the soprano carries the 1st countersubject, the alto carries the 2nd countersubject, and a free voice in the tenor rounds out the 4 voice harmony, all in expected common practice style.
A 3 voice episode of 10 bars follows which modulates to the relative key (b minor), where the subject enters in the soprano, the 1st countersubject in the tenor, the 2nd countersubject in the bass, and a free voice is assigned to the alto.
Another 3 voice modulating episode brings the music to the subdominant relative (e minor), where the subject enters in the bass, the 1st countersubject in the alto, the 2nd countersubject in the tenor, and the free voice in the soprano.
Another 3 voice episode of 4 measures follows, after which the subject enters again, this time in the alto, the 1st countersubject in the tenor, the 2nd countersubject in the soprano, and the free voice in the bass.
After this, another 4 voice episode modulates to the dominant key (A) where the subject enters in the bass, the 1st countersubject in the soprano, the 2nd countersubject in the alto, and the free voice in the tenor.
A sequence of 4 measures follows which leads into the stretto section and builds to 4 voices over a tonic pedal point; this 4 voice texture is retained straight through the coda until the final chord, which is expanded to 6 voices.
Creating something like this is proof positive that we know how to write a classroom fugue according to the general rules of part writing and the rules of common practice and still have it come out to be tuneful and interesting music.
In this work we note that in 11 different measures 2 different voices meet at a "near miss" interval of a minor 2nd (or it's dissonant cousin, a minor 9th), which introduces a little "sparkle," color, and spice and generates additional interest [See blog, Getting Started With Writing, Part XXI, Do The Unexpected].
Any time we spend studying and learning how a "jig" fugue like this is put together is time well spent.
It's necessary to caution organists, as they contemplate the study needed to embark on writing their first fugue, about the kind of textbook (Cherubini's "Course of Counterpoint and Fugue" is the most notorious) which purports to lay down regulations as to the requirements of a "properly written" fugue, and which is contradicted at every turn by the real music of the fugues of masters like Handel and J.S. Bach.
Fugue writing, as the student will quickly learn, is a vast subject where the scope for variety is almost infinite; the only real way for the student to come to realize the immensity of that scope is to make a careful study of many good examples.