Development of a session system with acoustic instruments

Abstract

AbstractIn this paper the authors describe the development of a session system which follows human performance and creates an improvisational accompaniment. One of the features of this system is that it can use acoustic instruments such as pianos and guitars instead of MIDI instruments which are common in conventional session systems. In a session system, complex sounds such as chords must be input, and the input musical information must be analyzed in real time. The authors' system can recognize chord names in real time through signal processing that takes advantage of the fact that instrument sounds are harmonics, while observing the restriction that detailed musical information such as the pitch of the sounds comprising a chord or the accuracy of the duration of sound production are not analyzed. The recognition rate for four‐note chords using thirds was shown in an experiment to exceed 95% using this method. In addition, the function which extracts the smallest repetition unit from a piece of music automatically allows for a session system that does not need to know the score beforehand. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 84(9): 20–30, 2001