"You're only as good as your worst song," says OneRepublic's front man and chief songwriter Ryan Tedder. Not that he knows anything about writing a dud. The 30-year-old born in Tulsa, Oklahoma, has obsessed over the art of pop music for more than a decade. Along the way, he's worked with Rihanna, Beyonc, Kelly Clarkson, Carrie Underwood, Jennifer Lopez, Leona Lewis (he shared a 2008 Best Record Grammy nod for her "Bleeding Love"), and other massive stars. And it's all lead him back to his own Denver, Colorado-based band, where he pours out his most heartfelt music.