207. A deceptive cadence is the progression of the dominant chord to some other chord than the tonic, the word deceptive implying that the ear expects to hear V resolve to I and is deceived when it does not do so. The most common form of deceptive cadence is that in which V (or V7) resolves to VI. It is used to give variety, but as in the case of the half-cadence, is not available at the end of a composition. Fig. 71 gives an example.
208. A sequence is a succession of similar harmonic progressions, these resulting from a typical or symmetrical movement of the bass part. See Fig. 72.
The word sequence is also applied to a succession of similar melodic progressions, as in Fig. 73.
209. Modulation is a change of key without any break in the continuity of chords or melody tones. Harmonic modulations are usually effected through the medium of a chord, some or all of whose tones are common to both keys. Examples of both harmonic and melodic modulations are shown in Figs. 74 and 75.