Score-Aligned Polyphonic Microtiming Estimation

Accurate estimation of note onset timing is important for music ensemble performance analysis and synthesis. In this study, we present a method for the detection of onsets from polyphonic mixtures, using score information. First, a MIDI score is aligned to the audio signal using dynamic time warping, and pitches of performed notes are refined using a multi-pitch estimation technique. Notes in a signal are then isolated using a spectral masking method, based on the average harmonic structure learned from each source. Onset timing is finally estimated by maximizing the time derivative of the energy curve of the note within an observation window. We show that this method significantly improves the onset timing estimation accuracy, measured by both the align rate and onset time deviation, and outperforms a state-of-art reference method.