Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Brain and Cognitive Sciences, February 2007.Includes bibliographical references.The origins and adaptive significance of music, long an elusive target, are now active topics of empirical study. I argue that empirical results can constrain discussions of the adaptive significance of music by testing whether various musical traits are innate, uniquely human, and specific to music. This thesis extends the body of empirical research along these lines, with a focus on comparative experiments in nonhuman animals. A series of studies in nonhuman primates explores whether they have preferences for sounds that might be related to music perception in humans. A second set of studies explores whether preferences for music can be instantiated in nonhuman animals by exposure to music. One study examines pet dogs, who receive extensive exposure to music courtesy of their owners. Another examines the effect of artificial music exposure on a colony of laboratory monkeys. Although there are a few potential homologies between the human response to music and that of nonhuman animals, the bulk of our results suggest dramatic differences between humans and other species. This leaves open the possibility of uniquely human music-specific capacities that might constitute an adaptation for music.by Joshua H. McDermott.Ph.D.