Whether knowledge of history and trends in the area is a cause or an effect of jazz appreciation remains somewhat a moot question. There is no question, however, but that Lillian Erlich's introduction to the lore, to the personalities, to the jargon is an excellent history for the neophyte and a well-chosen guide for the virgin ear. She begins with the rhythmic influences of West African slaves, the ring shouts, the song-sermons, the field hollers and the work songs tracing trends right on up to Gunther Schuller's ""Thied Stream"" merger. The personalities, the only somewhat expurgated biographies, are here too from Huddle Ledbetter to Thomas A. Dorsey, W.C. Handy, Scott Joplin, Bessie Smith, Louis Armstrong, Duke Ellington, Lester Young, Stan Kenton and Art Blakey. Assuming the young reader is ready to go from page to disc, the approach is and the presentation excellent. One of the first in this area for the young adult.