I begin with the proviso that, when discussing “evolution” in this book,I am, unless otherwise stated, referring toDarwin’s theory of evolution bynatural selection. This will be defined more formally in §1.5.1. As will bediscussed in §1.8, other theories of evolution have been developed, but thesewill not figure extensively here. At first thought, evolution might seem tobear little relation to most people’s experience and understanding of music.To the teenager absorbed in the sounds emanating from her headphones, thechild haltingly learning his first notes on the clarinet, or the retired personguiltily dividing her attention between the Beethoven symphony playingin the concert hall and the text message from her granddaughter, evolution– insofar as these individuals may apprehend the details of the theory – isprobably something they see as quite separate from their varied experiencesof music. These cultural stereotypes aside, however, I contend that evolutioncan shed a powerful light on music and, as explained in §1.2, it is the aim ofthis book to show how and why this is the case. The illumination of musicby evolutionary theory works in two main ways.