I had exactly the same problem - my "rant" was deleted by a moderator - no more "rant like" than some of the commentary on this discussion - and of course no actual useful advice was given... hey ho .....Net net I struggled with problem playing preferences etc
In the end I installed "ecoute" so I could at least listen to my music without the spinning beach ball (it interface with iTunes playlists etc) and seems to work without the delays.
Certainly does not solve the problem and I agree 100% with all the comments it should not be necessary and that Apple really should do better.... but at least I can now enjoy the music until they fix iTunes which should be both Urgent and Important.
Just thought I would share in case some folks were running out of patience and wanted to enjoy their music.