MWSCCS: A Stochastic Concurrent Music Language

Brian J. Ross

Brock University
Department of Computer Science
St. Catharines, Ontario, Canada L2S 3A1


The paper describes a music coruposition language MWSCCS - the Musical Weighted Synchronous Calculus of Communicating Systems. MWSCCS is a stochastic language based on Tofts' WSCCS and Milner's SCCS algebra. Main features of MWSCCS are its straight-forward approach to probabilistic execution, the ability for processes to generate musical events autonomously or to communicate amongst each other, the ability to write prioritized reactive processes, and its concise, hierarchical set of operators. MWSCCS diverges from the pure WSCCS algebra by introducing various devices useful for music, for example, a MIDI mappable event space, and stream repetition for the generation of repetitive melodies and rhythms. MWSCCS's execution engine consists of a search mechanism, which replaces the pure algebra's denotational semantics over streams. The implementation of the language benefits from the formal semantic definition of the original process algebra. The language is implemented in Prolog. Work is under way in creating compositions with MWSCCS that exhibit interesting chaotic and self-organizing behaviours.