unison chants of the Greeks and the Gregorian tones of the early
church, in which there isone melodythough many voices may
unite in singing it. Later we shall see what important princi-
ples for the growth of instrumental music were borrowed from
the instinctive practise associated with the folk-song and folk-
dance. But history makes clear that the fundamental principles
of musical coherence were worked out in the field of music known
as thePolyphonic. By this term, as the derivation implies, is
meant music the fabric of which is made by the interweaving
ofseveralindependent melodies. For many centuries the most
reliable instrument was the human voice and the only art-music,
i.e., music which was the result of conscious mental and artistic
endeavor, was vocal music for groups of unaccompanied voices
in the liturgy of the church. About the tenth century, musicians
tried the crude experiment,[11] called Organum, of making two
groups of singers move in parallel fifthse.g.,
[Music: Tu Patris sempiternus es Filius.]
but during the 13th and 14th centuries a method was worked
out by which the introductory tune was made to generate its
own subsequent tissue. It was found that a body of singers
could announce a melody of a certain type and that, after they
had proceeded so far, a second set of singers could repeat the
opening melodic phrase—and so likewise often a third and a
fourth set—and that all the voices could be made to blend to-
gether in a fairly harmonious whole.[12] A piece of music of this
systematic structure is called aRoundbecause the singers take
up the melody inrotationand at regular rhythmic periods.[13]
The earliest specimen of a Round is the famous one “Sumer is
icumen in” circa 1225 (see Supplement of musical Examples No.
1), which shows to what a high point of perfection—considering
those early days—musicians had brought their art. For, at any
rate, by these systematic, imitative repetitions they had secured
the first requisite of all music, coherence. This principle, once
it was sanctioned by growing musical instinct, and approved by
convention, was developed into such well-known types of poly-
phonic music as the Canon, the Invention and the Fugue; terms
which will be fully explained later on. It is of more than pass-
ing interest to realize that these structural principles of mu-
sic were worked out in the same locality—Northern France and
the Netherlands, and by kindred intellects—as witnessed the
growth of Gothic architecture; and there is a fundamental affin-