The Phrase-group
A second method consists in enlarging the
period-form to three phrases, by the same process of addition which, as
explained in the preceding chapter, transforms the single phrase into
the double-phrase or period. In order to preserve the continuity of
the three phrases, it is evident that the second phrase must also
close with a semicadence,--the perfect cadence being deferred until the
last phrase is concluded.
This form, be it well understood, does not include any of the
triple-phrase designs which may result from merely repeating one or the
other of the two phrases that make a period, as is shown in Ex. 48.
All such phrase-clusters as are reducible to two phrases, because
nothing more than simple repetition has been employed in their
multiplication, should always be classed among ordinary periods; for
two successive phrases, if connected (that is, unless they are
purposely broken asunder by a definite perfect cadence at the end of
the first phrase) always represent the analogy of Question and Answer.
The enlarged form we are at present considering consists of three
different phrases, as a general rule; probably very closely related,
or even distinctly resembling one another; but too independent,
nevertheless, to constitute actual repetition, and therefore to admit
of reduction to two phrases. For this very reason it cannot justly be
called period at all, but takes the name of phrase-group. An
illustration by diagram will make the distinction clear:--
Observe that the classification depends upon the number of
phrases,--upon the melodic identity of the phrases,--and upon the
quality of the cadences.
No. 1 is illustrated in Ex. 15; No. 2, in Ex. 42 and the first four
measures of Ex. 43 (cadence not perfect, it is true, but same
phrase-melody and same cadence); No. 3 is seen in Ex. 44
(phrase-melody similar, but cadences different)--also in Ex. 47; No. 4
is seen in Ex. 48; No. 5 is rare, but an example will be discovered in
Lesson 8; No. 6 is illustrated in the following (Grieg, op. 38, No.
2):--
Comparing this sentence with Ex. 48, we discover the following
significant difference: There, no more than two phrases were present;
the whole sentence was reducible to two phrases. Here (Ex. 50),
however, no such reduction is possible; three sufficiently similar--and
sufficiently different--phrases are coherently connected, without
evidence of mere repetition; it is the result of Addition, and the form
is a phrase-group. The first cadence is, strictly speaking, a
perfect one; but of that somewhat doubtful rhythmic character, which,
in conjunction with other indications, may diminish its conclusive
effect, and prevent the decided separation which usually attends the
perfect cadence. This is apt to be the case with a perfect cadence so
near the beginning (like this one) that the impression of conclusion
is easily overcome. In a word, there is no doubt of the unbroken
connection of these three phrases, despite the unusual weight of the
first cadence. See also the first cadence in Ex. 51.
By simply continuing the process of addition (and avoiding a decisive
perfect cadence) the phrase-group may be extended to more than three
phrases, though this is not common.