Light baton : a system for conducting computer music performance

Increasing attention is currently being given to the problem of an effective synchronization in live performance, between musicians and electronic synthesis system, in order to add a satisfactory degree of human sensitiveness to computer music. The authors of this paper developed a man-machine interface for controlling human instrumentalists and computers at the same time. The system recognizes the movements and the gestures that conductors usually perform in accordance with international standards. The interface consists of a special conductor baton, and a personal computer with a special image acquisition board connected to a CCD camera. The movements of a small lamp on the top of the baton are detected by the camera, digitized as the light point position changes, and properly stored. A best fitting interpolating method is used for carrying out the corresponding path, for increasing time resolution and for predicting beat points. Information extracted in the analysis are: beat point prediction, order number of the beats, amplitude of gestures, end of movement, absence of light points. The data produced are then used for affecting the musical performance. This system is usually used for synchronizing musicians and computers; furthermore, it can be used for learning conductor movements for controlling real-time algorithmic compositions.