Rossignol, S., Desain, P., and Honing, H. (2001) Refined knowledge-based pitch tracking.Proceedings of the International Computer Music Conference. San Francisco: ICMA.

Abstract

This paper presents an elegant method to obtain reliable and precise f0-trajectories from monophonic audio fragments that can be used for the analysis and modeling of vibrato in music performance. To model the vibrato during notes and in note transitions accurate f0-trajectories are needed. The proposed pitch extraction method takes advantage of the fact that the score, the timing, the instrument and even the fingering is known. The pitch extraction method is divided in three stages. In the first stage the audio signal is fed through a band-pass filter bank. For each harmonic one time-varying band-pass filter is used which adjusts its width and central frequency according to the pitch information in the score. Information from the instrument is used to adjust the bandwidth to the pitch and to the speed of transitions. In the second stage the frequency and energy trajectories are computed for each partial, using the signals obtained in the previous stage. In the final stage the FN and amplitude trajectories obtained are merged to provide the optimal f0-trajectory. Here the instrument information is used to decide on the correct interpretation in situations where, e.g., a higher partial is known to be a louder or more reliable source of f0 information than the fundamental itself, or where the tracks of certain harmonics of certain pitches are known to be distorted by sympathetic resonance.

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