Book excerpt: Epstein investigates the relationship between the ineffable art of music and the hard science of neurobiology. He integrates philosophic and scientific inquiry to formulate a theory of the fundamental yet elusive quality in music time. Derived from an analytical study of motion, tempo and emotion, Shaping Time offers a theory of the way we percieve, perform and interpret music. Epstein suggests that audience satisfaction with a musical performance results from timing trajectories established by the performer at the beginning of the piece. When the timing of a performance conflicts with audience anticipation, listeners experience physical and affective discomfort. Epstein applies his thesis to a wide range of examples for the repertoire.