This book argues that the need for music, and the ability to produce and enjoy it, is an essential element in human nature. Every society in history has produced some characteristic style of music. Music, like the other arts, tells us truths about the world through its impact on our emotional life. There is a structural correspondence between society and music. The emergence of 'modern art music' and its stylistic changes since the rise of capitalist social relations reflect the development of capitalist society since the decline of European feudalism. The leading composers of the different eras expressed in music the aspirations of the dominant or aspiring social classes. Changes in musical style not only reflect but in turn help to shape changes in society. This book analyses the stylistic changes in music from the emergence of 'tonality' in the late seventeenth century until the Second World War.