Blues People by LeRoi Jones. 1963, ISBN 0-688-18474-X.
Subtitle: The Negro experience in White America and the music that developed from it.
This book is about African-American music. How it got started with the slaves from Africa and their work songs, to Gospel, to Blues, to Ragtime, to early Jazz and to the various forms of Jazz that developed up until about 1960. (At least the edition I read stops at about 1960.) Doesn't discuss Rock or any more recent musical forms. Very interesting, written at a College level.
Purchased at Cameron's 1996 for $2.50.