Page:Fugue by Ebenezer Prout.djvu/157

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Chap. IX.]
Fugue.
139

293. The same form, though with some modifications, which we shall proceed to point out, is clearly to be seen in every well-written fugue. Its first section comprises the exposition and counter-exposition, when there is one, or (if there be no counter-exposition) it may also include an entry of subject or answer after the first episode, provided such entry be in either of the keys of the exposition. It will be remembered that the whole of the exposition oscillates, if we may so speak, between the keys of the tonic and dominant. If at the end of the exposition, the first episode modulates, so as to introduce an entry of the subject or answer in a new key, then the first section of the fugue ends with the exposition itself. For an illustration of this, see the passage from Bach's fugue in C minor, quoted in § 215. Here the exposition ends on the first note of the ninth bar, and the following episode, which modulates to E flat, to introduce the next entry of the subject, is the beginning of the middle section of the fugue. But if the first episode does not modulate away from the tonic or dominant key, but leads either to the counter-exposition, or to an isolated entry of subject or answer in the original key (as in our example (a) § 222) this episode and the following entry belong to the first section. To put it in general terms—The first section of a fugue extends as far as the end of the last entry of the subject or answer in the original keys of tonic and dominant. As a natural corollary of this, the second section begins with the commencement of the first episode which modulates to any other key than that of tonic or dominant.

294. The length of the middle section varies greatly in different fugues. In some it is very short, containing only one or two entries of the subject, connected by episodes of only a few bars' length. For instance, in the 31st fugue of the 'Wohltemperirtes Clavier,' a somewhat long exposition is followed by the counter-exposition in stretto which we quoted in § 270. Thus far all belongs to the first section of the fugue, because we never get away from the tonic and dominant keys. If the student will examine this piece he will see that, out of 70 bars which it contains, the exposition and counter-exposition extend to bar 44, or nearly two-thirds of the whole. There is only one episode in this fugue (bars 44 to 53), followed by an entry of the tenor in the key of the subdominant (bars 53 to 58), after which the reintroduction of the subject and answer in the tonic key (bars 59 to 70) form the final section of the fugue. The whole will therefore be analyzed thus—

First Section—Exposition and Counter-exposition (bars 1–44).

Middle Section—Episode and entry of subject in subdominant (bars 44–58).

Final Section—Return of subject and answer in tonic key: Coda (bars 59–70).

295. The disproportion in the length of the middle and final sections of this fugue, as compared with the first section, is