Techniques for expressive performance of electronic music with real-time, computer-controlled synthesizers
M. V. Mathews · The Journal of the Acoustical Society of America · 1990
Electronic instruments offer many new possibilities for the expressive performance of music. The intent of the performer must be embodied in physical gestures that control the sound. Gestures of arms, fingers, and articulators are the most rapid and precise movements that humans can produce. New sensors can be built to couple these notations to electronic instruments. An example is the radio drum, which continuously measures the positions of any number of drum “sticks” in three dimensions. The drum need not be “hit” to play a note. The trajectories of the sticks can be interpreted by a computer, much as the gestures of a conductor's baton are interpreted by an orchestra. Control programs can be written that allow the performer to concentrate his attention on the expressive factors of the music. The programs automatically supply the routine factors, factors over which the performer has no real choice, such as the sequence of pitches in a traditional score. One such program is the conductor program in which the score of the music to be played and positions of beats of the baton are stored in the computer memory. The performer controls the tempo of the performance by beating time with a stick or, in some cases, by moving the stick continuously to make a gradual change of tempo. Other continuous motions can shape timbral factors within notes or can control the loudness and balance of the different voices. The program allows much of the performer's gestures to be at the musical phrase level, rather than at the level of individual notes.