The disclosed technology provides for determining whether an audio stream is monophonic or polyphonic. An exemplary method includes analyzing and detecting frequency peaks in a portion of the audio stream. The method includes determining whether the portion of the audio stream is monophonic, by determining if all detected peaks are integer intervals of a lowest detected frequency peak. The method then includes determining that the audio stream portion is monophonic if a greatest common devisor frequency exists between a threshold frequency and the lowest detected frequency peak, wherein each detected peak is an integer multiple of the greatest common devisor frequency. The method includes determining that the portion of the audio stream is polyphonic if any one of the detected peaks is not substantially an integer multiple of the lowest detected frequency and if no greatest common devisor frequency exists between the threshold frequency and the lowest detected frequency peak.