is so little used as a form
at the present time: the modern composer demands a plan of
writing that is capable of being varied to such an extent as
to give him room for the exercise of his own particular
individuality of conception, and this the _canon_ does not do.
For this same reason too the fugue and the sonata have
successively gone out of fashion and from Schumann down to the
present time composers have as it were created their own
forms, the difficulty in listening arising from the fact that
no one but the composer himself could recognize the form _as_
a form because it had not been adopted to a great enough
extent by other composers to make it in any sense universal.
The result is that in much present-day music it is very
difficult for the hearer to discover any trace of familiar
design, and the impression made by such music is in
consequence much less definite than that made by music of the
classic school. It is probable that a reaction from this state
of affairs will come in the near future, for in any art it is
necessary that there should be at least enough semblance of
structure to make the art work capable of standing as a
universal thing rather than as the mere temporary expression
of some particular composer or of some period of composition.

142. The common _school round_ is an example of canon, each voice
repeating exactly what the first voice has sung, while this first voice
is going on with its melody. The _round_ is therefore defined as a
variety of canon in which the imitation is always in unison with the
subject.

143. The _fugue_ (Latin, _fuga_ = flight) is a form of contrapuntal
composition in which the imitation is always in the dominant key,
_i.e._, a fifth above or a fourth below. The imitation (called "the
answer") may be an exact repetition of the subject (sometimes called
"the question"), but is usually not so.

The _fugue_ differs from the canon also in that the subject is
given in complete form before the answer begins, while in the
canon the imitation begins while the subject is still going
on. The _fugue_ is not nearly so strict in form as the canon
and gives the composer much greater opportunity for expressing
musical ideas. A canon may be perfect in _form_ and yet be
very poor music; this same statement might of course be made
about any