Desain, P. and Honing, H. (in press) Modeling vibrato and portamento in music performance. Bulletin of the Council for Research in Music Education.
Research in the psychology of music dealing with expression is often concerned with the discrete aspects of music performance, and mainly concentrates on the study of piano music (partly because of the ease with which piano music can be reduced to discrete note events). However, on other instruments, what happens during and in-between notes can be even more relevant then the realization of the note onsets and offsets, an issue not often addressed in music psychology. A noteworthy exception is the work of Seashore (1938) who pointed out the importance of continuous aspects in music performance. However, while the current availability of signal processing techniques makes the continuous modulation signals (of e.g. pitch or dynamics) easier to extract, their shape is still quite complex. It is difficult to analyze and model them directly. In this presentation we describe an approach in which these signals are modeled by a composition of idealized components using an analysis-by-synthesis method (Desain & Honing, 1996). This proposed decomposition can be formalized and verified using the notion of generalized time functions that was developed for the construction of control functions for sound synthesis (Desain & Honing, 1992). Once modeled, the continuous behavior for each note and each transition can be expressed again as a discrete set of parameters, whose evolution over a series of notes can be linked to structural descriptions of the music. In this way we can adapt the methods developed specifically for discrete expressive attributes to the study of continuous aspects of musical expression.