An ancient evolutionary calculus for attention signaling retained in modern music

The ultimate mechanism(s) underlying the evolution of human music have been the subject of both philosophical thought and scientific study. However, the proximate mechanism of fitness signaled through the quality of music has not. As music and dance functionally aim to hold an observer’s attention, we investigate features in sound that might stimulate attentive behavior in an audience. We propose a calculus of attention to both movement and sound to ascertain its f(x)=control=position, f’(x)=energy=change in position, and f”(x)=surprise=change in direction (CES). We develop software to extract CES, (B) dynamically map audio trajectories within the space of CES, and (C) measure performer stability within CES (i.e. signaling performance quality). When musical sounds are compared to animal vocalizations, human speech, and non-biological sounds including noise, we confirm that music maintains the highest stability in the space of CES. Attention signaling also differs significantly between experts versus novice musicians, adult versus immature bird songs, and is constrained by performance interactions with live audiences as well. We conclude that quality signaling via this calculus of attention within behavioral display reflects physics of observing bodies in motion, probably originating from selective pressure of intra/interspecific conflicts formed at the Ediacaran-Cambrian boundary, and retained in music today.