Learning of musical structures for automatic improvisation systems by Ken Déguernel, postdoctoral researcher at Ircam.

Abstract

This work is part of the "Creative Dynamics of Improvised Interaction" project (DYCI2) that aims at creating digital musical agents able to listen, learn and interact with human performers to generate creative improvisations. The aim of this work is to create a system able to learn the dependencies between several dimensions (e.g. pitch, harmony, rhythm…), take into account the form of music upon several levels of organisation (e.g. beat, measure, section…), and use this information to generate more creative and more artistically credible improvisations. 
I will first present a system combining interpolated probabilistic models with a factor oracle. The probabilistic models are trained on a corpus and provide information on the correlation between dimensions and are used to guide the navigation in the factor oracle that ensure a logical improvisation. The improvisations are therefore generated in a way where the intuition of a context is enriched with multidimensional knowledge. We create then a system creating multidimensional improvisations based on interactivity between dimensions via message passing through a cluster graph. The communications infer some anticipatory behaviour on each dimension now influenced by the others, generating consistent multidimensional improvisations. 
Then, I propose a method taking into account the form of a tune upon several levels of organisation to guide the music generation process. Phrase structure grammar are used to represent a hierarchical analysis of a chord progression and this multi-level structure is then used to enrich the possibilities of guided machine improvisation.
Finally, I will present the final results from the DYCI2 projects, in particular, the DYCI2lib, a FLOSS library for automatic improvisation.

Biography

Ken Deguernel is a doctor in Computer Music. His research interests include music informatics, formal language theory, semigroup theory, probabilistic models and musicology. In particular, his work focuses on the understanding, the analysis and the modelling of order and disorder parts of creative processes employed by musicians during improvisation and composition in different contexts and different styles.