Rhythm in Music: What is it? Who has it? And Why?

This article explores human rhythmic abilities and behaviors within a framework of evolutionary theory highlighting the need for research in this area to be grounded upon solid psychologically valid definitions of rhythm. A wide-ranging cross-species comparison of rhythmic or quasi-rhythmic behaviors is presented with a view to exploring possible homologies and homoplasies to rhythm in human music. Sustained musical pulse and period correction mechanisms are put forward as human-specific and music-specific traits. Finally hypotheses as to why these abilities may have been selected for—and uniquely selected for—in the course of human evolution are explored.