Musical Structure

This chapter explores the perceptual and acoustic characterization of timbre, its role in the identification of sound sources and events, the perception of sequential timbral relations, timbre&s;s dependence on concurrent grouping, its role in sequential and segmental grouping, and its contribution to musical structuring. Timbre perception depends on acoustic properties of sounds and how these properties are represented in the auditory system. The sensory dimensions making up timbre constitute indicators that collectively contribute to the categorization, recognition, and identification of sound events and sound sources. In addition to timbre&s;s involvement in concurrent and sequential grouping processes, timbral discontinuities also promote segmental grouping, a process by which listeners "chunk" musical streams into units such as phrases and themes. The spectrotemporal receptive fields representation is claimed both to capture source properties of musical instruments that are invariant over pitch and sound level and to provide a sound source signature that allows very rapid and robust musical source categorization.