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 Darwinian fitness signaled through music has not. As popular music and dance functionally aim to hold an observers attention, we investigate features in various sounds that might stimulate attentive behavior in an audience. We propose a calculus of attention to moving objects and sound to ascertain their f(x) = location = positional control, 1st derivative f(x) = energy = change in position, and 2nd derivative f(x) = surprise = change in direction. We developed statistical software to (A) analyze nine features of sound related to acoustic control, energy, and surprise (CES), (B) map dynamic song trajectories within the multivariate space of CES, and (C) measure how stable performances are within this space (i.e. signaling fitness). When musical sounds are compared to animal vocalizations, human speech, and non-biological sounds including noise, we statistically confirm that music maintains the highest stability in the space of CES. This fitness signal related to attention varies across musical genres and is also detected animal calls as well. Attention signaling also differs significantly between experts versus novice musicians, adult versus immature bird songs, and is constrained by musical performance interactions with live audiences as well. We conclude that audiovisual signaling via this calculus of attention to behavioral display reflects the physics of observing bodies in motion, probably originating from selective pressure of intra/interspecific conflicts formed at the Ediacaran-Cambrian boundary, and retained in modern music today.