Polyphony and Monophony Contrasted.—In the concrete, polyphonic music may be represented by a series of lines representing separate and distinct melodies; though a principal melody is always used, it is not supported by chords of harmonic structure but by other melodies, or transpositions of the same melody, so used as to contrast with and support each other. Polyphonic music was essentially melodic, and, as has been very aptly stated, is to be thought of horizontally. Monophonic music might best be represented by one horizontal line supported at intervals by short, perpendicular lines. In this case the horizontal line represents the only distinct melody, and the perpendicular lines the subordinate or harmonic support or accompaniment. The following example illustrates the process of using the same melody to furnish the principal idea and also the accompanying support, the latter being at the same time simply a transposition of the original melody.
Polyphonic Style. Bach Fugue. Subject (or melody) enters in measure one; again, transposed to the fourth below in measure three, and one octave below in measure ten. Enough is cited to show the horizontal structure of polyphonic music.
To present the idea more clearly and for the sake of contrast, a melody with accompaniment is shown in the next illustration, giving a single melody with the subordinate chord accompaniment, the chords in whole notes indicating the harmonic structure or basis.
Beethoven, Op. 24, Monophonic Style. Sonata for Violin and Piano. Melody enters in measure one with subordinate accompaniment.
Search for Structural Principles.—While this question of the relation of polyphonic music to modern music may not apply to the first step in the development of the polyphonic style, yet it furnishes a preface to a discussion of the earliest stages of polyphonic evolution. The period preceding the year 1000 A. D. was truly a period of fundamental research into the underlying principles of melodic and harmonic structure; but so crude and hesitating was the use of what was found that it is certain that polyphonic material was entirely misused until the birth of “measured music” dispelled this darkness by the enlightening influence of Proportion and Form. So many forms of musical growth, such as came in later years, were impossible without the mensural proportion, that is, music written so as to indicate duration, that this initial period gathered but a chaotic mass of musical material which was left undigested and unassimilated until the epoch of the Paris school.
Beginning of Polyphony in Greek Magadizing.—The music of the Middle Ages has great interest for the historian and the student. It stands between our music and the music of the ancients; it drove its roots deep into the ancient time and extended its branches far into the contemporaneous epoch. It is the struggle between the two elements, the changes foreshadowed and apparent that give such interest to the history of music in the Middle Ages.