From M.I.A. to Four Tet, Kanye West to Joanna Newsom—and the many sides of Radiohead, too—here are the albums who defined the decade A few things happened at the beginning of the decade that made people wonder if albums would still matter in 2009. There was Napster, which, as New Year's Day 2000 hit, was already a few months old and only getting bigger. And then, a little over a year and a half la