It must be noticed that, though this fugue contains three subjects and three expositions, like the great fugue analyzed in Chapter XI., §§ 400–402, yet it is not really a triple fugue, as the three subjects are never all heard together. It more nearly resembles a fugue with two countersubjects heard in succession (§ 174).
434. The fugue on a choral affords an illustration of the general principle so often referred to in these volumes, that in proportion as the difficulty of the task increases, greater freedom is allowed to the composer. This has been amply shown in our examples. By the time that the student is so far advanced as to be able to attempt a composition of this class, he ought also to have acquired sufficient experience not to permit his liberty to degenerate into license.