Charli XCX Reveals How Lorde Reached Out for 'Hunger Games' Soundtrack

Charli XCX is behind the catchy song "Boom Clap," and now she's gracing the cover of Billboard magazine. The 22-year-old has a rebel anti-pop star vibe, and 'The Insider With Yahoo' correspondent Keltie Knight got some juicy inside info from 2014's breakout star.