A Dynamic Timed-Language for Computer-Human Musical Interaction

In this paper, we present the programing of time and interaction in Antescofo, a real-time system for performance coordination between musicians and computer processes during live music performance. To this end, Antescofo relies on artificial machine listening and a domain specific real-time programing language. It extends each paradigm through strong coupling of the two and strong emphasis on temporal semantics and behavior of the system. The challenge in bringing human actions in the loop of computing is strongly related to temporal semantics of the language, and timeliness of live execution despite heterogeneous nature of time in the two mediums. Interaction scenarii are expressed at a symbolic level through the management of musical time (i.e. events like notes or beats in relative tempi) and of the 'physical' time (with relationships like succession, delay, duration, speed). Antescofo unique features are presented through a series of paradigmatic program samples which illustrate how to manage execution of different audio processes through time and their interactions with an external environment. The Antescofo approach has been validated through numerous uses of the system in live electronic performances in contemporary music repertoire by various international music ensembles.