A good introduction to the avant-garde and free jazz movement, with some good insight. However, Litweiler all too often gets in the way of the subject by weighing in with his opinions. There are some great descriptions of certain solos, and particular styles of the musicians, but when he doesn't like something, he makes it known. I feel that anybody thinking of reading this should at least be a little acquainted with the major artists of this movement, otherwise they may be unfairly swayed in their opinion right from the outset.
Also this was published almost 30 years ago, so it really only gets into the first and second wave of performers, without going too far into the longer careers either.