6. Anne Hathaway
Anne Hathaway's never exactly been shy about the fact that she can sing, but we've sort of been discovering it in increments. When she appeared in Ella Enchanted, she did a few cutesy pop songs. Yeah, she had a nice voice, but so do a lot of people. What really changed the game was arguably the one good thing to come out of the disastrous Oscar show she hosted with James Franco. As one of the prerequisite fillers, she did a humorous version of On My Own (because apparently someone's a Hugh Jackass and bailed on her). A lot of people tend to view this as her way of auditioning for the film version of Les Miserables, which was already being talked about by this point. It showed off her range, and it put the idea of her as a legitimate singer into the heads of some important Hollywood people. The gamble paid off, and two years later she gleefully collected her statuette for a truly impressive performance as Fantine in Les Mis.