On tempo tracking: Tempogram representation and Kalman filtering

We formulate tempo tracking in a Bayesian framework where a tempo tracker i s modeled as a stochastic dynamical system. The tempo is modeled as a hidde n state variable of the system and is estimated by a Kalman filter. The Kal man filter operates on a Tempogram, a wavelet-like multiscale expansion of a real performance. An important advantage of our approach is that it is po ssible to formulate both offline or real-time algorithms. The simulation re sults on a systematically collected set of MIDI piano performances of Yeste rday and Michelle by the Beatles shows accurate tracking of approximately 9 0% of the beats.