Book excerpt: In this concise and engaging analysis of rock music, music theorist Ken Stephenson explores the features that make this internationally popular music distinct from earlier music styles. The author offers a guided tour of rock music from the 1950s to the present, emphasizing the theoretical underpinnings of the style and, for the first time, systematically focusing not on rock music's history or sociology, but on the structural aspects of the music itself. What structures normally happen in rock music? What theoretical systems or models might best explain them? The book addresses these questions and more in chapters devoted to phrase rhythm, scales, key determination, cadences, harmonic palette and succession, and form. Each chapter provides richly detailed analyses of individual rock pieces from groups including Chicago; the Beatles; Emerson, Lake, and Palmer; Kansas; and others. Stephenson shows how rock music is stylistically unique, and he demonstrates how the features that make it distinct have tended to remain constant throughout the past half-century and within most substyles. For music students at the college level and for practicing rock musicians who desire a deeper understanding of their music, this book is an essential resource.