I have purchased a lot of music on iTunes when I owned a PC. My PC had issues (really?) and I had to restore/reauthorize my music on the PC several times. When I purchased my MBP a few months ago and migrated my music to it, I received a warning that I would be unable to authorize the music any more.....so, in a couple of months when I buy my iPhone, what will I be able to do to move my music to the iPhone? Thank you in advance!