Mr. Machlis, author of The Enjoyment of Music and Professor of Music at Queens College of The City of New York, has contributed a worthy and much-needed addition to Norton's distinguished list of fine books about music. He illustrates his more general information on the background and trends in contemporary music by more technical analyses of specific, representative works. All of the latter selections are available on recordings, which the reader should use to accompany the textual information. Mr. Machlis divides his book into three main sections: Part One describes the development of twentieth-century concepts of melody, harmony, tonality, rhythm, texture, orchestration and form; Part Two deals chronologically with both major and minor developments in Europe with particular emphasis on the three giants Stravinsky, Bartok, and Hindemith; and Part Three deals chronologically and comprehensively with ""The American Scene"". There are five appendices, among them an extremely useful ""Survey of Basic Concepts"" by way of background material in music theory for each chapter; a suggested list of books for further understanding of the subject: and a list of specific recordings to accompany the textual material in the various chapters. This is a desirable addition to the libraries of all music lovers but will probably have its largest market with students of music.