1. A method of generating track data from an audio signal, the method comprising: generating a set of note onset events, each note onset event being characterized by at least one set of note characteristics, the set of note characteristics comprising a note frequency and a note timbre; identifying a plurality of audio tracks present in the audio signal, each audio track being characterized by a set of track characteristics, the set of track characteristics comprising at least one of a pitch map or a timbre map; and assigning a presumed track for each set of note characteristics for each note onset event, the presumed track being the audio track characterized by the set of track characteristics that most closely matches the set of note characteristics.