iTunes Match and Apple ID
I purchased iTunes Match and got it set up on my Apple ID. I then had to change my email address, and changed my Apple ID to reflect that new email. And for some reason my iTunes will not play any of my music under my previous ID. So I "turned off" iTunes Match and then signed on to iTunes Match with my new email address/ID. It synced all of the music I have purchased/downloaded since starting iTunes Match, and that's it. So I'm missing a large majority of my music.