Rhythmic notation and musical analysis of sperm whale vocalizations

Sperm whale (Physeter macrocephalus) vocalizations exhibit several universal features of human (homo sapien) music, including isochronous beats, metric subdivision, and the formulation of motivic patterns. Codas, which are short stereotyped click sequences made often in social interaction, most embody the three features listed above. We transcribed human music, randomly generated rhythms, and sperm whale codas in western musical notation, to best describe any rhythmic subdivision, meter, and syncopation present in sperm whale codas. When we tested the accuracy of our transcriptions, their complexity, and frequency of repeated phrases, the transcriptions of codas very closely resembled human music. We analyzed the notated codas for tempo modulation and motivic variation, finding interesting but as yet inconclusive patterns. Codas transmit cultural, social, or even (it has been argued) behavioral information in a communication system of as-yet unclear complexity. If the presence of meter in codas is significant to this system, then an understanding of the metric beat is essential to analyze the information encoded in sperm whales’ variation and syncopation. Our sample size was small and our tools were time-consuming, so more research is needed to fully test the applicability of these tools on a large scale.