lar phrases, in the same
composition. In other words, the omission of an expected cadence (or the
insertion of an additional one) may be an _occasional_ occurrence,--not
necessarily constant. See, again, No. 22 of the Songs Without Words; the
first and second phrases are small; the third phrase, however (reaching
from measure 6 to 9 without cadential interruption), is of regular
dimensions.

THE PRINCIPLE OF EXTENSION.--The other cause of modified phrase-dimension
is one of extreme importance, as touching upon the most vital process in
musical composition, namely, that of _phrase-development_.

Setting aside all critical discussion with reference to the question,
"What is good music?" and simply accepting those types of classic
composition universally acknowledged to be the best, as a defensible
standard (to say the least), we find that such a page of music exhibits
the pursuit of some leading thought (melodic motive or phrase), with
precisely the same coherence and consistency, the same evidence of
determined aim, as is displayed in the creation of a forcible essay, a
masterly poem, an imposing architectural plan, or any other work of art
that betrays intelligence and a definite, fixed, purpose. This is no
more nor less than might be expected from the dominion of the law of
Unity.

The equally inflexible demands of Variety are satisfied by presenting
this self-same leading thought in ever new and changing aspects,--_not_
by exchanging the thought itself for a new one at each successive angle.
This latter faulty process would naturally lead to a conglomeration of
impressions, baffling comprehension and jeopardizing real enjoyment.

In a classic page of music we perceive that each successive unit grows,
more or less directly, out of those which go before; not so directly, or
with such narrow insistence as to produce the impression of sameness and
monotony, but with such consistency of design as to impart a unified
physiognomy to the whole. Hence, it will often be found that every
melodic figure, during a certain section (if not the whole) of a
composition, may be traced to one or another of the figures which
characterized the first phrase, or the first two or three phrases, of the
piece. This was emphasized by our reference, near the end of the first
chapter, to the 8th Song Without Words of Mendelssohn. If the student,
in analyzing the melody of that composition, will endeavor to penetrate
some of the clever