<P>This work, which has become a classic in music theory since its publication in 1983, models music understanding from the perspective of cognitive science. The point of departure is a search for a grammar of music with the aid of generative linguistics. The theory, which is illustrated with numerous examples from Western classical music, relates the aural surface of a piece to the musical structure unconsciously inferred by the experienced listener. From the viewpoint of traditional music theory, it offers many innovations in notation as well as in the substance of rhythmic and reductional theory.</P>