I saw a good book at London's ICA bookshop yesterday - Thurston Moore on the artform that is the compilation cassette. Some of the best music I've heard was given to me either on a well-meaning mix-tape, or a whole-show recording of Andy Kershaw or John Peel's shows.
Some of the real gems were tracks that weren't 'first-listen-standouts.' Some of the best music of the last few decades didn't get the audience it deserved because it lacked an immediate impact.
Another artform was the ubiquitous 'bootleg' cassette from Camden Market in the '80s. Of course we should remember that home taping is killing music. So don't visit this bootleg site, do you hear?
Obviously, I didn't buy the book. I photocopied it instead.