imitations be at any regular distance. Sometimes they are so, as in our examples to §§ 222, 223; at other times, as in the second part of our quotation in § 225 (d), the distances of imitation are irregular.
231. Sequential treatment, important as it unquestionably is, is by no means the only point to consider with regard to episodes. A no less necessary requisite is variety. Each episode must have some feature which has not been seen in any of the preceding episodes. A mere transposition of one episode into a different key will be invariably weak and bad if no modification be made. On the other hand, some of the best episodes are made by repetition of an earlier episode with inversion of _parts. This gives the requisite variety, and at the same time preserves the artistic unity.
232. Beyond these general principles, it is impossible to teach the student how to write episodes for his fugues, excepting by showing him how the great masters have written them. It is here (just as with the "free fantasia" of a sonata or symphony) that the composer's imagination has the fullest scope. So long as he keeps within the bounds of the artistic and beautiful, he may in this part of the fugue do whatever seems good in his own eyes; and it will be in this part of the work, more than in any other, that his originality (if he have any) will be likely to assert itself.
233. Besides its use for the purposes of modulation, the episode serves, as already said, to separate the different groups of entries, or isolated entries, of the subject. We shall see, when we come to treat of the middle section of a fugue (Chap. IX.), that there is no restriction as to the number of these middle entries. Sometimes they are very few, at other times they are numerous. Consequently we find great differences as to the number of episodes in different fugues. For example, in the 'Wohltemperirtes Clavier' the 31st fugue has only one episode, and the 16th only two; but the 3rd, 12th, and 15th have six each. The number will depend entirely on the number of middle entries.
234. The length of the episodes is as variable as their number. In the majority of fugues they are comparatively short—often only two or three bars each; and in many cases it is better not to have too long an interval between the different entries of the subject. But they are occasionally found of considerable length. For instance, of the six episodes in the fugue in C sharp major (No. 3 of the 'Wohltemperirtes Clavier'), the first four and the last do not exceed four bars in length, but the fifth extends to fourteen bars. In the F major fugue (No. 35 of the same work) is seen a very unusually long episode of 28 bars. This, however, is quite an exceptional case. The composer's feeling of proportion and balance must be his guide in deciding both on the number and length of his episodes.
