ANDERS FRIBERG & GIOVANNI UMBERTO BATTEL
The communication of structure in musical expression has been studied scientifically by analyzing variations in timing and dynamics in expert performances. The underlying principles have been extracted and models of the relationship between expression and musical structure formulated. For example, a musical phrase tends to speed up and get louder at the start and to slow down and get quieter at the end; mathematical models of these variations can enhance the quality of synthesized performances. We overview the dependence of timing and dynamics on tempo, phrasing, harmonic and melodic tension, repetitive patterns and grooves, articulation, accents, and ensemble timing. Principles of structural communication (expression) can be taught analytically by explaining the underlying principles and techniques with computer-generated demonstrations, or in traditional classroom or lesson settings by live demonstration.
Variations in timing and dynamics play an essential role in music performance. This is easily shown by having a computer perform a classical piece exactly as written in the score. The result is dull and will probably not affect us in any positive manner, although there may be plenty of potentially beautiful passages in the score. A musician can, by changing the performance of a piece, totally change its emotional character, for example, from sad to happy (chapter 14). How is this possible, and what are the basic techniques used to accomplish such a change? The key is how the musical structure is communicated. Therefore, a good understanding of structure—whether theoretic or intuitive—is a prerequisite for a convincing musical performance.
This chapter surveys the basic principles and techniques that musicians use to convey and project music structure (see also overviews in Gabrielsson, 1999; Palmer, 1997). We will only consider auditory communication and leave out