Mōd/ū-lā'tion, n.
n. [Lat. modulatio, Fr. modulation, Pr. modulacio, Sp. modulacion, It. modulazione.]
Sense 1. The act of modulating; or the state of being modulated; as, the modulation of the voice.
Sense 2. Sound modulated; melody.
Sense 3. (Mus.) The manner of ascertaining and managing the modes; or, more generally, the art of conducting the harmony and air through those keys and modes which have a due relation to the fundamental or original key; a change or passing from one key to another. Moore.