CHAPTER XII.
THE RISE OF POLYPHONY. OLD FRENCH AND
GALLO-BELGIC SCHOOLS.
I.
E here enter upon one of the most interesting and important chapters in the history of music. The art of polyphony had its origin at the same period as the pointed arch and the great cathedrals of Europe, which our architects strive in vain to surpass. In the province of music it represents the same bounding movement of mind, filled with high ideality, which gave rise to the crusades, and poured out in their support such endless treasures of life and love. And in the same country, too, arose the Gothic arch, the beauties of the shrine of Notre Dame in Paris, and the involved and massive polyphony of music. Polyphonic is a term which relates itself to two others, as the leading types of all effort toward the expression of spirit through organized tones. They are Monodic and Homophonic. The musical art of the ancients was an art in which a single melodic formula was doubled in a lower or higher octave, but where no support of harmony was added, and where the only realization of variety could come through the province of rhythm alone; or, perhaps, to a very limited extent through changes in the mode or color of the scale from which the melody had been derived. Monodic art was an art of melody only, rhythm finding its explanation and source in the words, and so far as we understand the case, scarcely at all in the music. Our modern art of homophony is like that in having but a single melody at each moment of the piece; but it differs from the ancient in the important particular of a harmonic support for the melody tones composed of "chords in key." This harmonic accompaniment rules everything in modern music. It is within the power of the composer to confirm the obvious meaning of the melody tone by supporting it with the chord which would most readily suggest itself, within the narrowest limitations in the concept of key; or, second, it is within his reach to impart to any tone, apparently most commonplace, a deeper and a subtler meaning, by making it a peculiarly expressive tone of some related key. Instances of this use of harmonic accompaniment are numerous in Wagner's works, and form the most obvious peculiarity of his style, and the chief reason why the hearers to whom his works were first presented did not recognize the beauties and the novelties of poetic expression in them. Half way between these two types of musical art stands polyphony, which means etymologically "many sounds," but which in musical technique means "multiplicity of melodies." In a true polyphony not only has every tone of the leading voice a melodic character, but all the tones which sound together with it are themselves elements of other and independently moving melodies. Polyphony comprehends the most recondite elements of musical theory, but its essence consists of one leading concept—that of canonic imitation. The simplest form of this is furnished by that musical construction known as "round," in which one voice leads off with a phrase, and immediately a second voice begins with the same melodic idea at the same pitch, and follows after. At the proper interval a third voice enters and follows the procession at a corresponding distance behind. Thus, when there is only one voice singing we have monody; when the second voice enters we have combined sounds consisting of two elements; and when the third enters we have at each successive step chords of three tones. If there are four voices, as soon as the fourth enters, we have combined sounds of four elements. This form of musical construction was much practiced in England, as already noticed. A round, however, does not come to a close, but goes on in an endless sequence until arrested arbitrarily by the performers. Such a form is not proper to art, since it lacks the necessary element of completeness, for at whatever point it may have been arrested there was no innate reason why it might not have gone on indefinitely.
The polyphonic compositions of the schools in consideration in the present chapter go farther than this. While they consist of imitative treatment of a single subject carried through all the voices, or of several subjects which come together in such a way that the ear is not able to follow them as individuals, there is a conclusion, and the canonic imitation has a legitimate ending. Besides those compositions consisting of repetitions of the same subjects, these schools gave rise to other works in which several subjects are treated more or less in the same manner as a single subject would have been in a simpler composition. Nevertheless, in the earlier stages of the development, all the chords arose as incidents, and not as ends. The composer brought in his leading melodic idea at the interval prescribed or chosen. If crudities arose when all the voices were employed, he took no notice of them; the hearers, apparently, being too intent upon following the individual voices to notice the forbidden parallels of fifths or octaves, which inevitably arose until the composer had learned which intervals might be used without harmonic offense, and which not.
Before proceeding to the story of this chapter, the definition of a few terms may be advisable, in the interests of clearness. By "imitation," then, we mean the exact repetition of the melody of one part by another part, at the same or a different pitch. Such an imitation may be "strict," as when the intervals and progressions are exactly repeated; or "free," as when certain changes are made here and there in order to lead the imitation around better to the principal key. Canonic imitation is one in which the imitation is strict, the repeating voice exactly repeating the melody of the principal. By "counterpoint" we mean a second voice added to a melody already existing, the counterpoint having a strict relation to the leading melody, but a wholly independent movement. This conception had its origin in the art of extemporaneous descant, in which, while the choir and congregation repeated the melody of the plain song, a few talented singers performed variations to it, guided solely by ear and tradition, returning to the tone of the plain song at all the points of repose. We do not know when extemporaneous descant gave place to written composition, but it was probably early in the twelfth century. By "double counterpoint" is meant a counterpoint which, although written to be sung an octave lower than the principal song, can be transposed an octave and sung higher than the principal song without giving rise to forbidden progressions. This will be the case only when the original relations of the two voices have been restricted to certain prescribed intervals. By "fugue" is meant a form of composition in which every voice in turn enters with the leading melody of the piece, the same given out by the leading voice at first, called the "subject," responding alternately in tonic and dominant. This form comes later than the period we are now about to consider, but it grew out of the devices of polyphony, and accordingly is always to be kept in mind as the goal toward which all this progress was tending.
The art of polyphony is to be understood as an effort toward variety and unity combined. The unity consisted in all the voices following with the same melodic idea; variety, in the different combinations resulting in the course of the progress. The limitations of polyphony were reached when the true expression of melodic intervals was lost through their intermingling with so many incongruous elements.