Modalys: a Synthesizer for the Composer-Luthier-Performer

The advent of digital sound synthesis has offered to the musical researcher the possibility of exploring the concept of musical instrument in its broader sense. One principal axis of interest of the IRCAM Musical Acoustics Team is research on modelisation of musical instrument oscillation, the computer implementation of the models that arise, and the evaluation of the musical interest that the computer implementation may have. The program Modalys is the result of years of work in this direction: Modalys is an open environment where virtual acoustical instruments may be imagined, performed and manipulated. In this paper we present an overview of the ideas and results that make Modalys a powerful and particular tool used by computer musicians. The paper is split into several parts: a theoretical introduction to modal synthesis, a description of the synthesizer and its features, a discussion of its musical possibilities and a description of Modalyser, a graphical interface of Modalys intended for nonprogrammers. History of the project In 1987, after experience with traditional synthesis methods and physical modeling, Jean-Marie Adrien became interested in the applications that Modal Analysis theory could provide to the field of sound synthesis. Modal Analysis has been, since as long ago as the nineteen fifties, an important tool that mechanical engineers use in the study of vibration. In 1988, Adrien wrote a set of Unix programs in C which became the preliminary version of Modalys. His research and results are described in his Ph. D. thesis on acoustics (1988). In 1990, Joseph Morrison rewrote Modalys to make it operational for musical production. This new version, which was written in C++ on a NeXT computer, featured Modalys as an extension of Oliver Laumann's Scheme interpreter (1994); in addition, it integrated the research of E. Ducasse (1990) and O. Calvet (1990) into new physical algorithms. The elegant design of the 1990 version of Modalys has proven to be solid, and is still the basis of the program in its current version;