opus

opus ōˈpəs [key] [Lat.,=work], in music, term used in cataloging a composer's works, designating either a single composition or a group published together or considered a unit. Opus numbers assigned by the composer are of greater value than those assigned by the publisher. Beethoven was the first composer whose use of opus numbers was consistent enough to be of value.

See more Encyclopedia articles on: Music: Theory, Forms, and Instruments