Chapter 4

CHAPTER III

POLYPHONIC MUSIC; SEBASTIAN

BACH

We have traced, in the preceding chapter, some of the funda-
mental principles of design in musical expression, as they were
manifested in the Folk-music of the different nations. All music
of this type was homophonic,i.e., a single melodic line, either
entirely unaccompanied or with a slight amount of instrumen-
tal support. Hence however perfect in itself, it was necessarily
limited in scope and in opportunity for organic development.
Before music could become an independent art, set free from
reliance on poetry, and could attain to a breadth of expression
commensurate with the growth in other fields of art, there had to
be established some principle of development, far more extensive
than could be found in Folk-music. This principle[32] of “The-
matic Development”—the chief idiom of instrumental music—by
which a motive or a theme is expanded into a large symphonic
movement, was worked out in that type of music known as the
Polyphonic or many-voiced; and Polyphonic music became, in
turn, the point of departure for our modern system of harmony,
with its methods of key relationship and of modulation. As
we have stated in Chapter I, the principle of systematic rep-
etition or imitation—first discovered and partially applied by
the musicians[33] of the early French School and by the Nether-
land masters—finally culminated in the celebrated vocal works