late 14c., "act of singing or making music," from Old French modulation "act of making music" (14c.), or directly from Latin modulationem (nominative modulatio) "rhythmical measure, singing and playing, melody," noun of action from past participle stem of modulari "regulate, measure off properly, measure rhythmically; play, play upon," from modulus (see module). Meaning "act of regulating according to measure or proportion" is from 1530s. Musical sense of "action of process of changing key" is first recorded 1690s.
If we may take him at his word Arnold Schoenberg has a system of modulation.
Her modulation of grief, in her plaintive pronunciation of the interjection, Oh!
This is their modulation to the dominant, their awakening to life.
The modulation into an easy-going friendship was not difficult for these young people.
We note this modulation particularly in Pellas and Mlisande.
First would come a few detached sentences, like a modulation.
After all, it is the modulation that carries the message of the text.
This modulation is forbidden; therefore it must not be made.
Greta spoke like the wardresses, in a tone out of which all modulation had gone.
When he spoke, his voice was a monotone lacking any modulation of feeling.