1. The process of changing from one key to another.
2. In electronic music, the term is applied to a change of frequency, amplitude, or other changes of similar nature possible through electronics.

SUGGESTED LISTENING EXAMPLES:

Modulation (1.):
Beethoven: Symphony No. 7 in A major, Op. 92, II (modulation)

W. W. Norton - 4-CD Musical Example Bank -- Disc 2, Track 51

Rodrigo: Concierto de Aranjuez for Guitar and Orchestra, I (development)

W. W. Norton - 4-CD Musical Example Bank -- Disc 1, Track 64