This book was the culmination of more than 25 years of empirical and theoretical research in the field of music. In the first part, Stumpf discusses the origin and forms of musical activities as well as various existing theories on the origin of music, including those of Darwin, Rousseau, Herder, and Spencer. In the second part of the book, he summarizes his works on the historical development of instruments and music, and studies a putatively global range of music from non-European cultures to demonstrate the psychological principles of tonal organization, as well as providing a range of cross-cultural musical transcriptions and analyses. This became a fo