Calder's Violin: real-time notation and performance through musically expressive algorithms

Notation is a central issue in modern western music. Composers have often sought ways of expanding and refining the functionality of notation and, in doing so, have re-shaped the music that they were originally aiming to describe. Other musical traditions have very different uses for notation; some have no use for it at all; each approach creates contrasting musical experiences. The role that electronics and computers have played in music has also influenced the nature and function of notation. More traditional 'live' notation of note/pitch- based music generated algorithmically has proved particularly problematic: musical notation is itself a very complex subject. Composers and technologists have instead used libraries of images, algorithms for the pre- generation of material or simplified notations that can be used as the basis of more improvisatory performances. This paper presents work involving the live presentation of 'traditionally precise' music notation created through algorithmically generated material. This notation can then be performed by a human musician alongside computer-generated diffused sound or other 'real' musicians. Technologies used include the SuperCollider audio programming environment and the INScore notation project with the Open Sound Control protocol used to communicate between them. As well as providing a fascinating musical experience, the process highlights a number of issues concerning performance practice, instrumental technique, rehearsal, time and timing, as well as the nature of notation itself and its relationship to improvisation.