AbstractThe dynamic behaviour of piano mechanisms is of interest to many individuals. Pianists can benefit from some understanding of the way in which their movement of the piano keys affects the sound generated; the designers of piano mechanisms seek to achieve specific responses from the piano mechanism. These people need to know the relationships between the forces exerted by the pianist’s fingers and the movement of the piano keys and hammers. Moreover, researchers in such fields as kinesiology and experimental psychology believe that the detailed stud/of piano performance can provide new insights into skilled human motor performance in general.A computer simulation has been developed that can be used to model the dynamic behaviour of a piano mechanism. Given the motion of the piano keys the simulation can be used to find the corresponding motion of the hammers (predicting the time of impact of hammer on string to within one millisecond), and the forces exerted on the keys. This paper describes the theoretical formulation of the model, and the methods used to gather calibration data. The application of the model in a system to monitor piano performance is described, and other possible applications are discussed.