late 14c., "small bagpipe," from Old French musette "bagpipe" (13c.), from muser "to play the bagpipe, make music," from mus "mouth, muzzle," from Medieval Latin musum (see muzzle (n.)). By 1788 as "a composition for or as though for a musette," a quiet pastoral melody, usually in imitation of a bagpipe, from this sense in French.
MUSETTE. The name of an air generally written in common-time, and the character of which is always soft and sweet. From the style of this air, dances were formerly invented of a similar cast, and which were also called Musettes. Musette was also the name formerly given to a small kind of bagpipe much used in most countries of Europe, the performers on which were called Musars. [Thomas Busby, "A Complete Dictionary of Music," 1806]