Music is central to human cultural and intellectual experience. It is vitally important for the welfare of human society and - this book argues - should become more widely accepted in our community as a mainstream educational and therapeutic tool. This book explores the importance of music throughout human evolution, and its continued relevance to modern-day human society. Throughout, the emphasis is on the origin of music and how (and where) it is processed in our brains, exploring in detail the genetic and cultural evolution of modern, loquacious humans, how we may have evolved with unique neural and cognitive architecture, and why two complementary but distinct communication systems - language and music - remain a human universal. In addition the book explores, in some depth, the different theories that have been put forward to explain why musical communication was (and remains) advantageous to our species, with a particular emphasis on the role of music and dance in enhancing altruistic and prosocial behaviours. The author suggests that music, and the social harmonization it brings, was of vital importance in early humans as we became more and more individualized by the emergence of modern language and the modern mind, and the realization that we are mortal. 'Music, Evolution, and the Harmony of Souls' demonstrates the evolutionary sociobiological importance of music as a driver of cooperative and interactive behaviour throughout human existence, and what this evolutionary imperative means to twenty-first century humanity and beyond, from social and medical/neurological perspectives