a real-time multimedia framework, which was in part developed at the MML.

As a side-effect, we have implemented a general framework for handling parametric curves of arbitrary dimension. The framework, a number of Java classes, can automatically handle interpolated intervals, derivative and similar operations on coordinate axes. In addition, it is possible to iterate trough parameter intervals at an arbitrary resolution.

The new version of the PerformanceRubette will be available as part of RUBATO (see http://www.rubato.org).

6 Conclusions and Future Work

We have presented the concept of gesture spaces and curves as an extension to the existing score-performance model in performance theory. The use of parametric gesture curves will help realising avatars performing in a virtual environment, thus adding a further level of reality in computer-aided performance. This is particularly true when used in combination with complex instrument parameter spaces, which are used for sound synthesis of a physical instrument model. Further, the ‘freezing’ mechanism of symbolic gesture curves can be used for an abstract recording of musical gestures and therefore provides a powerful theoretical basis for instance for the design of new instruments and gestural interfaces.

Currently, work is mainly focused on how physical gesture curves can be constructed. The basic idea is to first construct a curve making use of the same mechanisms as in the symbolic domain, and then to apply physical constraints, in order to deform the symbolic curve step by step. This includes correct handling of a geometric hand model, including finger transitions. One of the main problems here is to solve the inverse kinematics equations given by the coordinates of the