Patent ID: 6057502
Filing Date: 2000-05-02
Classification: G10H

Abstract:
An apparatus for recognizing musical chords from incoming musical sound wave data representing a musical sound wave of a musical performance including musical tones based on a reference tone pitch of the musical performance, said apparatus comprising:a frequency component extracting device which extracts frequency components in the form of a frequency spectrum having peaks in level from said incoming musical sound wave data;a frequency range cutting out device which cuts out frequency component data included in a predetermined frequency range from said extracted frequency component data;an octave profile creating device which folds and superpose the cut-out frequency component data on the basis of the frequency width of an octave span to create an octave profile of the musical sound wave in the form of a frequency spectrum having peaks in level, said octave span being defined based on a reference tone pitch predetermined for the apparatus;a pitch adjusting device which detects a deviation of the reference tone pitch of said incoming musical sound wave from the reference tone pitch in the apparatus and shifts the frequency axis of said octave profile by the amount of said detected deviation;a reference chord profile providing device which provides reference chord profiles respectively for a plurality of chord types, each chord profile exhibiting a pattern of frequency components existing at frequency zones each of a semitone span corresponding to chord constituent tones for said each chord type; anda chord determining device which compares the pitch-adjusted octave profile with said reference chord profiles to find a reference chord profile that coincides with said pitch-adjusted octave profile, thereby determining the chord established by the incoming sound wave.