Short three-part fugue (32-36 mm). Details in class.
Typically this will be an exposition, three developing phrases, and a recapitulation in which the subject-answer pair is restated entirely in the home key.
The exposition typically consists of one well-formed subject-answer pair imitating at the 5th, a second subject entry imitating at the octave in the third voice, and an episode following that subject entry, in which the third voice utilizes material from the countersubject, sequentially, to reach a full strong cadence in V or III.
In total, the exposition of a 3-part fugue is really two large phrases.
1. The first is the subject-answer pair which together form a progression that tonicizes the dominant and then (with a “linking” passage) returns to the tonic. During the answer, the subject voice continues in invertible counterpoint against the answer; this material is the “countersubject”. The end of the “link” that returns to the tonic is the beginning of the second phrase, where the third voice enters with an imitation of the subject at the octave.
2. The second phrase begins by replicating the chord progression implied by the subject, exactly; it only differs from the opening statement of the subject by having three voices instead of one. During the second subject entry, the voice of the answer makes use of countersubject material (which needn’t be a strict imitation of the countersubject). Rather than proceed to the answer, a sequential treatment of countersubject material in the third voice (called an “episode”) leads to the related key, completing the second phrase with a strong cadence.
3. Just as is the case with 2-part inventions, the cadence is not a stopping point for the piece, but a launching pad for the next phrase.
The remaining phrases of the fugue are structured very much like those of a two-part invention.
Since the answer and countersubject are related to each other as invertible counterpoint, it will now be possible to reiterate the the relationship between them in several new transpositions, and several new part relationships. Fugue 17 (A-flat major) from WTC I is one possible model for a short-subject, tonal-answer fugue; a detailed, hand-written diagram of its phrases was given and discussed in class. Note that this fugue is in four voices, offering plentiful examples of its subject in various stages of development. Your assignment is to write a three-voice fugue, which is a somewhat less daunting task.
Phrases use subject-answer pairs, subject statements alone, and sequential bridges, to progress between related keys. Like two-part inventions, fugues do not cease their rhythmic motion until the end of the last sentence: the recapitulation of the subject-answer pair in the home key area.