The fruition of musical score by means of multimedia systems requires a suitable model for automatic or interactive expressive music performance. The authors present a method for controlling the mutable musical expressiveness in an abstract way, not necessarily working directly on the acoustic parameters. Our approach integrates symbolic and audio processing in a real-time networked environment. We present a mapping strategy allowing one to control and vary the expressiveness in a coherent way, by means of an abstract "control space". All the variations computed by the model on the symbolic representation are successively managed by the signal processing sub-system which coherently transforms the sound by a combination of different audio effects. The signal processing engine works in real time to render the desired expressive audio variations. The model is used interactively in a Web-based environment. The user controls the expressive character of the performance by moving within an appropriate control space.
