I am taking a music appreciation class this term and we are using Roger Kamien's Music: An appreciation. We have been asked to buy the 9 cd set (which is around $100). There is also a 5 cd set (around $50). With that much difference in price I was wondering if it was really worth it to buy the 9 cd set. If anyone has taken this class or used these cds if you can let me know the major differences between the two. As well as if there is anywhere to find the track listings for both sets as I have not been able to find them.