USING PATTERNS TO GENERATE RHYTHMIC ACCOMPANIMENT FOR GUITAR

Overview & Synopsis

This work presents the model of a system that generates guitar rhythmic accompaniment of a song, given its chord grid and melody. In order to minimize the effects of the lack of formal knowledge which inherently exists in this musical dimension, the system uses a very natural approach in music: the contextualized reuse of rhythmic patterns, found in performances of famous musicians. To accomplish this task, two techniques of artificial intelligence were combined: case-based reasoning, for the modeling the "musical memory" (association of rhythmic patterns and the context where it should be used) and rule-based reasoning, to associate abstract intentions to the contextual characteristics of the patterns. As a case study, we developed Cyber-João, a program that generates a rhythmic accompaniment for Bossa Nova by chaining and adapting rhythmic patterns found in classic records of João Gilberto. Finally, the model was empirically compared with some other approaches implemented to solve the problem, demonstrating very motivating results.