Definition: The act of modulating, or the state of being modulated;
as, the modulation of the voice.
Definition: Sound modulated; melody.
Definition: A change of key, whether transient, or until the music
becomes established in the new key; a shifting of the tonality of a
piece, so that the harmonies all center upon a new keynote or tonic;
the art of transition out of the original key into one nearly related,
and so on, it may be, by successive changes, into a key quite remote.
There are also sudden and unprepared modulations.
