The method of manipulation is ingenious; observe the variety obtained by the striking dynamic changes from _ff_ to _pp_; and, hand in hand with these, the changes from major to minor, and back (as shown by the inflection of _b_-flat to _b_-double-flat).

These are first applied to members only, of the Antecedent, as indicated by the brackets _a_ and _b_, and then to the entire Consequent phrase.
Observe, also, that in the repeated form of the latter, the rhythm is modified to a smoother form, during two measures.

The result here achieved is constant Unity and constant Variety from almost every point of view, admirably counterbalanced.
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.
{78} 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.