G IT

lock-based physical modeling is a methodology for modeling physical systems with different subsys-tems. It is an important concept for the physical modeling of real or virtual musical instruments where different components may be modeled accord-ing to different paradigms. Connecting systems of diverse nature in the discrete-time domain requires a common inter-connection strategy. This contribution presents suitable inter-connection strategies that incorporate a wide range of modeling blocks and considers the automatic implementation of block-based structures. Software environments are presented, which allow to build complex sound synthesis systems without burden-ing the user with problems of block compatibility. Physical modeling for digital sound synthesis evolved around 1990 [1]–[4] and has since then produced a variety of modeling paradigms for all kinds of sound production mechanisms [5]–[9]. Despite or because of this progress, modeling of real or virtual musical instruments seems to be a more complex task than ever. Since musical instruments consist of different com-ponents with different physical nature, there is no best method for physical modeling. However, choosing a different model for each component leads to a mixture of different numerical meth-ods that have to be carefully interfaced for a meaningful and reliable real-time operation and control. A strategy well known from the simulation of dynamical sys-tems is to separate the tasks of component modeling and model interaction. Modeling a component of a physical system means to identify the relevant quantities (force, deflection, pressure, velocity, etc.), to set up a mathematical description based on the basic laws of physics and to find a suitable discretization fo