In the following:
[Illustration: Example 35. Fragment of Schumann.]
the semicadence in the fourth measure is made with the dominant harmony of C major (the tones g-b-d-f); it is so disguised as to remove all signs of interruption; but the chord prevails throughout the measure, and (as may be seen by reference to the original, op. 68, No. 3) the next measure—the fifth—exactly corresponds to the first; this indicates another "beginning," and proves our "ending."
But though the dominant is thus generally employed at the semicadence, it is by no means the only available chord. It must be remembered that every cadence which does not fulfil the definite conditions of the perfect cadence, is a semicadence. Examine each of the following, and determine why the point of repose is each time a semicadence:—Ex. 1; Ex. 9, No. 3; Ex. 14, No. 2, fourth measure; Ex. 14, No. 3, fourth measure; Ex. 19; Ex. 22, Nos. 3 and 4; Ex. 23, No. 2, fourth measure.
The distinction between the two species of cadence becomes most subtle when the tonic harmony is chosen for the semicadence, but with some other part of the chord than the keynote as uppermost (or lowermost) tone. This might appear to lighten the perfect cadence too immaterially to exercise so radical an influence upon the value (weight) of the interruption. The keynote, however, is so decisive and final in its harmonic and melodic effect—everywhere in music—that its absence more or less completely cancels the terminating quality of the cadence-chord; in other words, the force of a tonic cadence depends upon the weight and prominence of the keynote.
For example:
