Ebenezer Prout · section 2 of 50

Introduction

Also in

Gradus ad ParnassumJohann Joseph Fux · imitationExercises in Elementary CounterpointPercy Goetschius · imitationCounterpoint AppliedPercy Goetschius · imitation and the strettoTreatise on HarmonyJean-Philippe Rameau · imitationCounterpoint AppliedPercy Goetschius · the canonGradus ad ParnassumJohann Joseph Fux · double (invertible) counterpointGradus ad ParnassumJohann Joseph Fux · the fugueCounterpoint AppliedPercy Goetschius · the fugue and the fugal expositionTreatise on HarmonyJean-Philippe Rameau · the fugueCounterpoint AppliedPercy Goetschius · the episode

The collection of preludes and fugues commonly known as " Das Wohltemperirte Clavier " consists in reality of two complete and separate works, each containing one prelude and fugue in each of the major and minor keys. The first, to which Bach himself gave the name which is now attached to both series, was completed in 1722, and owed its genesis to the controversy of the period on the question of equal versus unequal " temperament": an acoustical subject into which we need not here enter, beyond stating that the old methods of tuning sacrificed the "extreme" keys in the interests of precision of intonation in the simpler ones, whereas the present method distributes equally over the whole of the twelve semitones (or twelve " perfect" fifths) the slight deviations from absolute exactitude which are inseparable from our musical system, thereby reducing them almost to vanishing point. Bach demonstrates, what in our day seems the veriest commonplace, that by the aid of " equal temperament" it is possible to play in any key with equally good effect. The second collection, which was completed in 1744, was originally known, according to Marpurg, as "Twentyfour New Preludes and Fugues"; but inasmuch as it illustrates, in common with the first series, the value of equal temperament, no objection can be urged against the inclusion of both under the common title.

Bach's part-writing, in the fugues, is as absolutely clear and definite as though each part were given to a separate voice or instrument. The student who desires to obtain a thorough insight into them could not possibly devise a better exercise than to write them out in score, i. e., with each part on a separate staff. In any case he should number the bars in his edition, in order to facilitate reference. In the few fugues which are not written as beginning at the commencement of a bar (Nos. 11, 34, 36, 37, 48) we have reckoned the first complete bar as bar 1. In the three-part fugues we have described the parts uniformly as treble, alto and bass; in the four-part ones as treble, alto, tenor and bass; and in the two for five voices (Nos. 4 and 22) we have regarded the additional one as another treble.

The text followed has been that of the Bach-Gesellschaft.

DEFINITIONS.

FUGUE.—A contrapuntal composition (that is, with all the voices of separate melodic importance) founded on a concise theme called the " subject,” which is given out singly, and then according to certain rules, by each voice in turn, and subsequently developed. The form is an application of the " ternary "; that is to say, three principal divisions are recognizable, usually according to the keys employed, but occasionally according to the methods of treatment. The divisions are not always quite sharply defined, but the general scheme holds good in practically every case.

SUBJECT.—The theme on which the fugue is founded (but see “Answer"). If there are two or three subjects, the fugue is called a double or triple fugue.

ANSWER.—The transposition of the subject, usually into the key of the dominant, given to the second voice which enters, as a companion to the subject (hence the terms " dux " and " comes,” sometimes used instead of subject and answer). The first entries of the remaining voices usually alternate between the subject and answer, but there are occasional exceptions. There are two kinds of answer. Real Answer is an exact transposition of the subject. Tonal Answer is one more or less modified according to the exigencies of tonality; Its principle is that a conspicuous dominant in the subject (or a modulation to the dominant key) is better answered by the tonic (or tonic key) than by the supertonic, which is only " secondary" in relation to the key. Hence certain notes are answered a fourth higher (or fifth lower) whereas in a real answer everything is copied a fifth higher (or fourth lower). In the later parts of a fugue, the distinction between subject and answer is not always maintained.

COUNTERSUBJECT.—A counterpoint which accompanies the subject with more or less regularity. Of course, except in a double fugue, it does not accompany the first entry of the subject, but first appears with the answer. If the counterpoint which accompanies the answer is not recurrent, it is better not to describe it as a countersubject. In the "exposition" (see below) the countersubject is usually found in the voice which has just had the subject or answer.

EXPOSITION.—The first giving out of the subject and answer by the several voices, together with any countersubjects and other incidental matter. Normally one entry is given to each voice. Not infrequently there is also a redundant entry, or second entry of the voice which led originally. Much more rarely, the entry of one voice is reserved for a later section of the fugue.

COUNTER-EXPOSITION.—An optional second exposition, giving a second group of entries in the original keys (tonic and dominant) but quite differently arranged, the voices entering in changed order, or those which had the subject having the answer, and vice versa. Often the counter-exposition is only partial, i. e., not participated in by all the voices.

MIDDLE SECTION.—The modulatory portion of the fugue, the keys, as a rule, being other than those of the exposition. Entries of the subject, either in groups or isolated, alternate with "episodes" (see below), and the subject often undergoes important changes of treatment. Sometimes these new methods of treatment (" stretto," " inverse movement," etc.) give sufficient freshness to obviate the necessity for new keys.

FINAL SECTION.—The portion which returns to, and contains one entry or more in, the original key or keys.

EPISODE.—An interlude, generally for purposes of modulation, between the entries of the subject. That is, a portion of the fugue in which the subject and answer are absent. It rarely corresponds to the episode in other musical forms (contrasted material), but rather to " development," being usually founded on matter contained in the exposition. Episodes are found chiefly, but not exclusively, in the middle section of a fugue.

CODA, CODETTA.—There is no special significance attached to the application of the word Coda to fugue. It is the close of the piece, often of similar construction to the episodes, often, on the other hand, containing some final elaboration of the subject. Codetta is a short passage appended to an entry, not to the entire composition, and is only distinguished from an episode by its function, or sometimes by its length or by its degree of individuality. As a good generalisation—though subject to some reservations—a codetta separates entries that belong to the same group, or merely supplies a cadence to an entry, while an episode separates those belonging to different groups, making the modulations. Thus the term codetta is chiefly used in connection with the exposition, where a group of approximated entries is always expected; but it is sometimes needful to use it later in the fugue.

STRETTO.—An overlapping of two entries of the subject (or subject and answer); one voice entering before the previous one has completed its course. Stretto maestrale is a stretto in "canon" (see below), each voice completing the subject instead of breaking away from or modifying it on the entry of a new voice.

IMITATION.—The copying of a passage or rhythmic figure, more or less strictly, and at a short interval of time, by a different voice.

CANON.—Strict, note-for-note imitation (though it may be at any interval) throughout a passage of some length. Canon (or stretto, or imitation) "at the octave," or "in the octave" is used to denote the interval separating the entries.

INVERSE MOVEMENT (INVERSION).— A metamorphosis of a subject, countersubject or other melody, by the substitution of ascending intervals for descending, and vice versa.*

COUNTERPOINT, DOUBLE, TRIPLE OR QUADRUPLE.—Two, three or four melodies capable of inversion one with another in any order, i. e., making correct harmony whichever be placed at the bottom, or as a middle part, or at the top. Double counterpoint in the octave (or "at the octave") is that in which the inversion is normal, the lower part being placed an octave higher, or the higher an octave lower; in the tenth is when the pitch of the inverted part is altered a tenth (compound third); in the twelfth when the alteration is a twelfth (compound fifth).

NOTE.—It is assumed that the terms belonging to simpler branches of musical theory, such as "cadence," "sequence," "pedal point," are already familiar to the student.

* In order to avoid even a possibility of confusion, the editor prefers to use only the term " inverse movement " in this sense, confining " inversion " to its harmonic signification. But the author's M.S. has not always been altered, and it may, therefore, be well to point out that when we speak of the "inversion" of two subjects, or themes, we mean their changed relation one to the other (double counterpoint), and it is only when one theme alone is in question that the word inversion has been allowed to bear its other meaning (= inverse movement).