Musical Composition with Stochastic Context-Free Grammars

Abstract. In this paper we discuss the design of a generator of musi-cal sequences for the purpose of aiding musicians in their compositional work. A series of steps were abstracted to reflect composition as a se-quential flow of data refination; also each step involved in this process was modeled to gain each one of their functions. Specifically, in the case of the main structure of the suggestion a stochastic context-free grammar was developed to generate harmonic progressions, in the case of rhythms a probabilistic model based on accents was also developed, and finally, to state individual notes of the suggestion another probabilistic model based in the dissonance of intervals was used. Each one of these models were structured upon J.S. Bach’s rules of homophonic composition as this was the target musical genre of the work