Charlotte Truchet (LINA, Nantes)

Constraint Programming (CP) allows to modelize and solve combinatory problems by specifying some partial information on variables, unknowns of the problem. It provides programming languages where the constraints are stated, and then passed to a solver which gives a solution. At first glance, CP seems well adapted to computer assisted musical composition, where composers are used to think by rules. We will investigate this hypothesis, relying on works in collaboration with IRCAM (french Institute for Research and Coordination Acoustics / Music).

We will first present some musical constraint problems, either stated by contemporary composers, or of musical analysis, or instrumentation, . Fourteen such problems have been modelized and solved, which allowed to give a detailed typology. This has been used to conceive and implement OMClouds, a library in the Computer Assisted Composition environment OpenMusic. It is based on a local search algorithm called adaptive search. Its architecture allows in particular to define a constraint problem visually, to solve it, and eventually to edit partial or approached results during the resolution process.