The impression has formed in the literature dealing with Darwin’s life and achievement that he was himself unmusical, and that his theories have offered little help in understanding or valuing the role of music in human society. This article draws on biographical information relating to Darwin’s family and household to illustrate that he was in fact surrounded by music throughout his life. While Darwin’s deterioration in health may have reduced his ability to appreciate music in later life, he was clearly much involved in music as a young man. He also employed music in several of his experiments in animal behaviour, involving members of his family as co-researchers. A close reading of The Descent of Man that forms the central focus of this article illustrates the extent to which, throughout the book, Darwin made reference to musical behaviours in defining and illustrating his themes of natural and sexual selection. Ensuing correspondence with his sons consulted in the Darwin Archive at Cambridge University Library conveys the difficulty he had in dealing fully with music as a human capacity in its own right. However, far from his having little to say about music, Darwin’s theories of natural and sexual selection robustly define the research agenda for exploring the purpose of music and its relation to language: a project that recent developments in neurology, anthropology and linguistics have begun to reveal in a new light.