Fugue (Prout)/Chapter 1

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1. It is absolutely necessary that any one who begins to study fugue should have a thorough knowledge not only of Harmony and Counterpoint, but of Double Counterpoint and Canon. Without such knowledge any attempt to master fugal composition is a mere waste of time. A previous acquaintance on the part of the pupil will therefore be presupposed throughout this work, either with the preceding volumes of the present series, or with other books treating of the same subjects.

2. A Fugue is a composition founded upon one subject, announced at first in one part alone, and subsequently imitated by all the other parts in turn, according to certain general principles to be hereafter explained. The name is derived from the Latin word fuga, a flight, from the idea that one part starts on its course alone, and that those which enter later are pursuing it.

3. Though the definition of Fugue just given may be accepted as generally correct, it should be mentioned here, to prevent misapprehension, that fugues may be written on more than one subject. If there are two subjects, the fugue is said to be a double fugue; if there are three, it is a triple fugue, and so on. In such cases the composition will not begin with one part alone; the subjects will appear together, although in all probability they will not all commence exactly at the same time. It must also be said that we often meet, especially in modern music, with vocal fugues having an independent instrumental accompaniment. In such cases what has been said as to the entry of the subject with one part alone does not apply; a fugue of this kind has some analogy to an accompanied canon.

4. From the description just given of fugue, it would seem at first sight to have a considerable resemblance to Canon. The latter, indeed, was formerly called fuga canonica, and it will greatly assist the beginner to understand the real nature of a fugue if we point out the chief differences between it and the canons which, it may be assumed, he has already studied. One most important difference is that, whereas in a canon the leading voice is imitated throughout by all the parts that follow, this is never the case in a fugue. The opening theme, known as the "subject," is always imitated; frequently also one or more of the accompanying counterpoints to the various imitations of the subject are themselves imitated, as will be seen later in this chapter; but continuous imitation of one part by another throughout the whole piece is scarcely ever met with in a fugue.[1] This is one of the most important distinctions between the two forms.

5. Another respect in which fugue differs from canon is that in the latter the imitation by the second voice must always be exact as to the name of the interval, though in many cases (as for instance in a canon in the ninth) the quality of the interval is changed (Double Counterpoint and Canon, §§ 339, 340[2]). In a very large number of fugues, on the other hand, the first imitation is not an exact copy of the subject, but requires more or less important modification, as will be explained later.

6. A third distinction between the forms which we are now comparing is that, while in a canon the first imitation may be at any interval, it must in a fugue be always at the distance of a fourth or fifth above or below the subject. This, it must be added, refers only to the commencement of a fugue; in its later developments the entries may be at other intervals.

7. Before proceeding to treat separately of the various parts of a fugue, it will be advisable to give a general description of its form, and an explanation of the names applied to the different parts. Fugues differ so much in their structural details that it is impossible to give more than a general outline here; the numerous variations will be noticed when in later chapters we treat of the various parts one by one.

8. The Subject of a Fugue is the theme announced in the first instance by any one part or voice without harmony (except in the cases mentioned in § 3), on which the whole composition is founded. By this it is not meant that the subject is to be heard continuously throughout the fugue; this would probably cause great monotony, although instances are to be met with (e.g., in the first fugue of Bach's 'Wohltemperirtes Clavier') in which the subject is rarely absent. What is intended is that the subject is to make its appearance, at more or less frequent intervals, throughout the whole of the fugue.

9. The Answer is the transposition of the subject into the key of the perfect fourth or fifth above or below the key of the subject. In an enormously large majority of cases the keys for the subject and answer will be the tonic and dominant; occasionally we find the answer in the subdominant instead of the dominant. (See § 71.) The answer will in the first instance be given by whatever voice has the second entry, and the choice of this voice, as will be seen later, will largely depend on what voice first announces the subject. The answer is frequently an exact transposition of the subject; in this case it is called a real answer; and a fugue which contains a real answer is said to be a "real fugue." At other times the answer is a modified transposition of the subject, alterations being necessitated by the form of the subject itself. Such an answer is called a tonal answer; and a fugue in which there is a tonal answer is called a "tonal fugue." The rules which enable us to decide whether an answer should be real or tonal will be fully discussed in Chapters III., IV.

10. The first voice, which announced the subject, should never be silent while the second voice is giving the answer. It always accompanies with a counterpoint, which may or may not be intended for subsequent use. If it be, it must be written in double counterpoint, so as to be able to accompany the subject or answer either above or below. A counterpoint which accompanies subject or answer systematically (though not of necessity invariably) is called a Countersubject. We sometimes meet with fugues which have more than one countersubject.

11. A fugue may be in any number of parts, but, whatever the number, they should all (with very rare exceptions) enter in turn at the commencement of the fugue with either the subject or the answer. That portion of the fugue which extends as far as the conclusion of the subject or answer (as the case may be) by the voice that last enters is called the Exposition of the Fugue.

12. The exposition is usually followed by the first Episode. An episode is that part of the fugue in which for a while neither subject nor answer is heard. It is usually founded upon some material taken either from the subject or from one of the accompanying counterpoints, in order to give unity to the composition as a whole. The episode is also employed for the purposes of modulation, as will be seen when we come to treat of it later.

13. The close of the first episode is sometimes, though not always, followed by what is called a Counter-Exposition. This is a second exposition in the same two keys as the first, but with this difference, that the voices which before had the subject now usually have the answer, and vice versa. Sometimes the counter-exposition precedes the first episode, and follows the exposition immediately. Very frequently also it is only partial; that is to say, only some of the voices, and not all, take part in it.

14. The counter-exposition, if there be one, will generally be followed by a second episode, different from the first one. To this second episode (or to the first, if there be no counter-exposition) succeeds the Middle Section of the fugue. Here a much greater amount of freedom is allowed to the composer; in fact, there are hardly two fugues the middle sections of which are identical in their construction. There are no restrictions in this section as to order, interval, or key of entry, though in the best models we mostly find that here the two principal keys (tonic and dominant) of the fugue, which have been almost exclusively employed during the exposition, are in general avoided, or only incidentally touched on. The entries of the subject in other than the chief keys of the movement are here also mostly divided by episodes.

15. The Final Section of a fugue is that in which a return is made to the original key. Here the subject appears once at least; very frequently the answer is also repeated. It is not uncommon, especially in vocal fugues, to find a Pedal point (Harmony, Chapter XX.) introduced toward the close of this final section. Sometimes there will be two pedal points; in this case a dominant pedal will come first, and a tonic pedal at the conclusion of the piece. Pedal points are also occasionally, though much more rarely, to be met with in the middle section of a fugue. A good example will be seen in the fugue in F major, No. 11 of the second book of Bach's 'Wohltemperirtes Clavier.'

16. An important feature of many, though by no means of all, fugues, is what is known as a Stretto. This is an Italian word meaning "close," and is applied to that part of a fugue in which the entries of the subject and answer succeed one another more closely, that is, at a shorter distance of time, than in the first exposition. For instance, if the subject be four bars in length, the answer will, in all probability, enter at the fifth bar. If, now, in the subsequent developments of the fugue the subject is followed by the answer (or by the subject itself) in another voice at the fourth, third, or second bar instead of the fifth, so that the first entry, so to speak, overlaps the second, we have a stretto. A stretto may be merely for two voices, or all the voices of the fugue may take part in it in turn. Very frequently we find more than one stretto in the same fugue. In that case the interest of the music is not only maintained, but heightened by making each successive stretto closer than the preceding.

17. We sometimes find fugues in which a stretto is seen in the first exposition, that is to say, in which the answer enters before the completion of the subject, not infrequently immediately after its commencement. A fugue of this kind is called a Close Fugue.

18. The old theorists used to draw a distinction between strict and free fugues. A Strict Fugue was one which either contained no episodes at all, or in which the material of the episodes was entirely drawn from the subject or countersubject. Most of the fugues in Bach's 'Wohltemperirtes Clavier' belong to this class. If the episodes were chiefly constructed on matter unconnected with the subject or countersubject, the fugue was said to be a Free Fugue. The fugue in Handel's overture to 'Samson' is an excellent example of a free fugue.

19. A strict fugue in which the various scientific devices, such as canonic imitation, augmentation, diminution, &c., were largely employed, was formerly known as a Ricercare, or Ricercata, that is a fugue with research. Two elaborate fugues, one for three and the other for six voices, in Bach's 'Musikalisches Opfer' are entitled "Ricercare." The name was also sometimes given to fugues without episodes.

20. We occasionally find fugues in which the answer, instead of being, as usual, a transposition of the subject (§ 9), is given by inversion, or by augmentation or diminution. We shall see examples of these as we proceed. Such fugues are called fugues by inversion, augmentation or diminution, as the case may be.

21. A fugue of only small dimensions, and not developed at any great length, is called a Fughetta—an Italian diminutive, meaning a little fugue. Many specimens of this kind are to be found in Bach's organ arrangements of chorals. A good example will also be seen in Beethoven's 'Thirty-three Variations on a waltz by Diabelli,' op. 120, at the twenty-fourth variation.

22. We very frequently meet with passages written in the fugal style, that is, in which a subject is announced in one part and imitated by the others, but in which the imitation is not at the regular intervals of reply of subject and answer. Such passages are called Fugato passages. A whole movement is sometimes written in this way; but more often fugato passages are introduced incidentally. The chorus "Their sound is gone out" in the 'Messiah' is an example of fugato.

23. It must be clearly understood by the student that what has been said in this chapter is to be regarded only as a very general description. There is, probably, hardly any other form of composition in which there is so much room for variation of detail as the fugue. Beyond the fact that all fugues contain an exposition, a middle section, and a final section, there is little or nothing that they necessarily have in common. The one point to realize is, that a fugue should be, so to speak, an organic growth, the materials of which are to be developed mainly from the subject and its accompanying counterpoints. How this is to be effected we shall endeavour to show in the following chapters, in which we shall deal in succession with the various portions of a fugue.

  1. As an exceptional instance of a fugue in which two parts are in canon throughout should be mentioned the 'Fuga canonica in Epidiapente' (i.e., in the fifth above) in Bach's 'Musikalisches Opfer.'
  2. The references to "Harmony," "Counterpoint," and "Double Counterpoint and Canon" throughout this work refer to the preceding volumes of this series.