Modulation

Webster's Dictionary of the English Language

·noun Sound modulated; melody.

II. Modulation ·noun The act of modulating, or the state of being modulated; as, the modulation of the voice.

III. Modulation ·noun 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.