Tatum grid analysis of musical signals

An algorithm for analyzing the rhythmic content of acoustic signals of polyphonic and multitimbral Western music is presented. The analysis consists of detecting sound onsets, computing an inter-onset interval (IOI) histogram, and estimating the duration of the shortest notes, i.e. the tatum period, from the histogram. Robustness against tempo changes has explicitly been built into the system by using short-term memory for the tatum grid estimation. The results are directly applicable to computational music processing for making a musically useful segmentation and computing a musical time base. The proposed algorithm works causally and a real-time software implementation is available on-line (see Seppanen, J. and Majdak, P., "Rhythm Estimator Software", ftp://iem.kug.ac.at/pd/Externals/RHYTHM/, 2000). The performance of the system was validated for 50 musical excerpts, and the algorithm was found to be capable of finding the tatum grid from music with a regular rhythm.