hich reference has just been made; for a tone of
greater length than its fellows is, in itself, the most conclusive
evidence of a point of repose, as compared with the shorter tones in
the course of the sentence, whose more prompt succession indicates the
action of the phrase. (See Ex. 29.)

From this the student is not to conclude that every long tone marks a
cadence. The rhythmic design of a melody is obtained by a constant
interchange of long and short tones, without direct reference to the
cadence alone; and numerous examples will be found in which tones of
equal, or even greater, length than the cadence-tone occur in the
course of the phrase. We have already seen that the end of a motive,
or even of a figure, may be marked by a longer tone, or its equivalent
in rests; and have been taught to expect a cadence in the fourth
measure only, as a rule.

But the direct evidence of a cadence afforded by a longer tone is
considered not only unnecessary, but in many cases distinctly
undesirable. While cadences are indispensable, in music of clearly
recognizable form, it is equally true that they must not be so emphatic
as to check the current of melody and harmony too frequently or
completely, or destroy the continuity and coherence of the members.
And it is therefore an almost invariable practice, especially in music
of a higher order, to modify and disguise the cadences by some means or
other; that is, to diminish the weight of the characteristic "longer
tone,"--to counteract, partially or entirely, the impression of actual
cadential cessation, by continuing (instead of interrupting) the
rhythmic pulse. This is so very common, and so confusing a device,
that the effect of the various methods employed to conceal or disguise
a cadence must be thoroughly understood.

It is necessary to remember, always, the rule that governs the actual
body of the phrase, and its possible preliminary tones; namely, that
the vital, essential starting-point of a phrase (and other factors of
musical form) is _the first primary accent_, the first beat of the
first _full_ measure. The length of the phrase is reckoned from this
point, and consequently, the cadence-chord is entitled to all the beats
that remain, from its accent to the very end of the final measure. For
example:

[Illustration: Example 19. Fragment of Mozart.]

In this case the cadence-chord is not modified or disguised in the
least, but takes full advantage of the six