In direct opposition to Nik Cohn's Rock From the Beginning (p: 344) both in approach and opinion, this is a careful, analytical presentation by an author who is both sound and savvy. His study takes you way back to Tin Pan alley kitsch and why it went out with the coming of the 45's. And on through the emergence and submersion of rock, folk, surf and country and western music to the transcending development and sound of the Beatles. Belz discusses subsidiary aspects -- skiffle music, why American Bandstand is unique in its survival, etc. He is also a responsible critic noting the ""self conscious"" style of the Ramsey Lewis Trio or the ""stylized and superficially complicated"" music of today's packaged Supremes (in comparison with their early work). In advancing his theory that rock is art, Mr. Belz delves into roots, heritage, ""soul,"" as well as performance. A lot of the discussion centers on the Beatles, and his dissection of their work is one of the best around. As is the book.