Patent ID: 8592670

Claim:
A computer-implemented method of detecting and identifying a note in an audio signal, comprising: converting a first portion of the audio signal from a time domain to a first frequency domain portion; detecting, in the first frequency domain portion, a peak at a fundamental frequency and detecting a first predetermined number of peaks at integer-interval harmonic frequencies of the fundamental frequency; converting a second portion of the audio signal to a second frequency domain portion; identifying the note by detecting, in the second frequency domain portion of the audio signal, a peak at the fundamental frequency and detecting a second predetermined number of peaks at integer-interval harmonic frequencies of the fundamental frequency, wherein the second predetermined number of peaks is less than the first predetermined number of peaks; storing in a computer memory indications of the existence of the fundamental and harmonic peaks; and outputting to a user a visual representation indicating the presence of the note in the audio signal portion when the indications are stored in the memory.