For an interresting read on this same general subject matter, I would reccommend "Music, the Brain and Ecstacy". I can't find my copy right now, so I don't have the author name, but the book is only a few years old and should be easily available. It takes all of the "Why do some chords sound good together while others create havoc in the ears?" questions, throws a bit of science into the mix and ends up stimulating and fascinating.