On the decidedly downbeat affair, Around the Sun, Michael Stipe & Co. finally reveal they have no interest in playing ''rock'' anymore not necessarily a bad thing, considering that the elegiac ''Leaving New York'' starts the album off strongly. But how to explain Q-Tip's limp guest rap on ''The Outsiders''? Our guess is that he was recruited while they were all chilling with Elton at Donatella's. Still, as arena folk goes, R.E.M. remain cooler than, say, the Wallflowers. Just barely.