Beat Critic: Beat Tracking Octave Error Identification By Metrical Profile Analysis
Computational models of beat tracking of musical audio have been well explored, however, such systems often make "octave errors", identifying the beat period at double or half the beat rate than that actually recorded in the music. A method is described to detect if octave errors have occurred in beat tracking. Following an initial beat tracking estimation, a feature vector of metrical profile separated by spectral subbands is computed. A measure of subbeat quaver (1/8th note) alternation is used to compare half time and double time measures against the initial beat track estimation and indicate a likely octave error. This error estimate can then be used to re-estimate the beat rate. The performance of the approach is evaluated against the RWC database, showing successful identification of octave errors for an existing beat tracker. Using the octave error detector together with the existing beat tracking model improved beat tracking by reducing octave errors to 43% of the previous error rate.
Leigh M. Smith
Proceedings of the 11th International Symposium on Music Information Retrieval, Utrecht, The Netherlands, 2010, pages 99–104.