Analyzing popular music from a musical, rather than a sociological, biographical, or political viewpoint, this book surveys Western popular music in all its forms—blues, ragtime, music hall, waltzes, marches, parlor ballads, folk music—to uncover the common musical language uniting these disparate styles. The author examines the split between "classical" and "popular" music in the nineteenth and early twentieth century, and presents a wealth of musical illustrations from the Middle Ages to the 1920s to trace the tangled roots of today's popular music. His provocative, readable, and comprehensive study will inform anyone with an interest in how music evolves in our society.