ry 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