in D♯ minor, no. 8, in the XLVIII, and many other celebrated instances.
By these and similar expedients, the one Subject is made to produce the effect of several new ones; though the new Motivo is simply a modified form of the original.
But a good Subject must not only suggest a good Answer: it must also suggest one or more subsidiary Themes so constructed as to move against it, in Double Counterpoint, as often as it may appear.[1] These secondary Themes are called Counter-Subjects (Contra-Subjectum; Contra-Tema; Contra-subjekt; Contre-sujet). The Counter-Subject or Counter-Subjects, however numerous they may be, must not only move in Double Counterpoint with the Subject, but all must be capable of moving together, in Triple, Quadruple, or Quintuple Counterpoint, as the case may be. Moreover, after the Subject has once been proposed, it must nevermore be heard, except in company with at least one of its Counter-Subjects. The Counter-Subjects usually appear, one by one, as the Fugue develops; as in Bach's Fugue in C♯ Minor—No. 4 of the XLVIII. Less frequently, one, two, or even three Counter-Subjects appear with the Subject, when first proposed, the Composition leading off, in two, three, or four Parts, at once. It was an old custom, in these cases, to describe the Fugue as written upon two, three, or four Subjects. These names have sometimes been erroneously applied even to Fugues in which the Counter-Subjects do not appear until the middle of the Composition, or even later. For instance, in Wesley and Horn's edition of Bach's XLVIII, the Fugue in C♯ minor is called a 'Fugue on 3 Subjects,' although the real Subject starts quite alone, the entrance of the first Counter-Subject taking place at bar 35, and that of the second at bar 49. Cherubini very justly condemns this nomenclature, even when the Subject and CounterSubjects begin together. 'A Fugue,' he says, 'neither can nor ought to have more than one principal Subject for its exposition. All that accompanies this Subject is but accessory, and neither can nor ought to bear any other name than that of Counter-Subject. A Fugue which is called a Fugue on two Subjects, ought to be called a Fugue on one Subject, with one Counter-Subject,' etc. etc. It is highly desirable that the nomenclature thus recommended should be adopted: but there is no objection to the terms Single and Double Fugue, as applied respectively to Fugues in which the principal Counter-Subject appears after or simultaneously with the Subject; for, when the two Motivi begin together, the term 'Double' is surely not out of place. When two Counter-Subjects begin together with the Subject, the Fugue may fairly be called Triple; when three begin with it, it may be called Quadruple; the number of possible Counter-Subjects being only limited by that of the Parts, with, of course, the necessary reservation of one Part for the Subject. A Septuple Fugue, therefore, is a Fugue in seven Parts, written upon a Subject, and six Counter-Subjects, all beginning together.
The Old Masters never introduced a Counter-Subject into their Real Fugues. Each Part, after it had replied to the Subject, was free to move wherever it pleased, on the appearance of the Subject in another Part. But this is not the case in the modern Tonal Fugue. Wherever the Subject appears, one Part, at least, must accompany it with a Counter-Subject; and those Parts only which have already performed this duty become free—that is to say, are permitted, for the moment, to fill up the Harmony by unfettered Counterpoint.
When the Subject and Counter-Subject start together, the Theme is called a Double-Subject; as in the last Chorus of Handel's 'Triumph of Time and Truth,' based on the Subject of an Organ Concerto of which it originally[2] formed the concluding Movement; in the 'Christe' of Mozart's Requiem; and in the following from Haydn's 'Creation.'
It is very important that the Subject and Counter-Subject should move in different figures. A Subject in long-sustained notes will frequently stand out in quite a new aspect, when contrasted with a Counter-Subject in Quavers or Semiquavers. In Choral Fugues the character of the Counter-Subject is usually suggested by a change in the feeling of the words. For instance, the words of the Chorus, 'Let old Timotheus,' in 'Alexander's Feast,' consist of four lines of Poetry each sung to a separate Motivo.
In order that the Subject may be more naturally connected with its first Counter-Subject, it is common to join the two by a Codetta (Fr. Queue; Germ. Nachsatz), which facilitates the entrance of the Answer, by carrying the leading Part to a note in harmonious continuity with it. The following Codetta is from the celebrated Fugue called 'The Cat's Fugue,' by D. Scarlatti.
- ↑ See Counter-Subject, vol. 1. p. 400.
- ↑ See the original MS., in the British Museum, George III. MSS. 310 [274. d.]
