hod of "imitation" was employed by all the
polyphonic composers. Continuity was assured; lovely or unlovely
harmonic dissonances were always arising, and being resolved through the
collisions and onward movement of parts; the music, both melodically
and harmonically, could be as expressive as the particular composer's
powers allowed. But the unity was the unity of a number of pieces of
wood of varying length laid so as to overlap and nailed together; the
superficial unity was due to the words; the real, essential unity
depended on all the music being the sincere expression of a steady
emotion--in those days religious emotion. Thus were attained the motet
forms and the Mass, and, when the method was applied to secular words,
the madrigal.

The earlier instrumental pieces were built after the same fashion--see
the "fancies" and organ compositions of the time; but in these there
were no words either to give the impulse or hold the bits together. With
the fugue, music, unaided by words, was held together by its own innate
strength; it became a self-sustaining One subject was generally taken;
others--oftenest one, sometimes more--were added; all the subjects were
passed about from part to part until the end of the composition, with
the interspersion of passages called "episodes" for the sake of
"variety." Here there was unity, continuity, with a vengeance. It was of
the very essence of the fugue that the motion should never be arrested;
if it seemed to halt for a moment, then, as in the older music, the
stopping-place was the jumping-off place for a fresh start. All the
severer men wrote in this form, most of them displaying marvellous
mathematical--and some of them, alas! mechanical--ingenuity; a few of
them, Bach towering high above the rest, attained a full and truthful
expression of deep feeling. Bach, for the organ alone, raised sublime
architectural structures, unapproachable, to use Schumann's word, in
their magnificence. But the underlying feeling was always the same
throughout; it might wax or wane in intensity: its character did not
change. The themes, once announced, were rigid and unalterable; the
music had always to be more or less like "a tune tied to a post."
Dramatic changes of mood had no place. So later, a voice had to be found
for shifting, complex, theatrically conflicting moods--states of mind
characteristic of the modern and not of the bewigged world. When Haydn
was still young the problem composers wer