In May 2009 Bieber unveiled his first single, the buoyant puppy-love song “One Time,” and six months later he released the seven-track EP My World, composed mainly of glossy R&B-influenced pop. By this time his audience had dramatically expanded to include countless preadolescent girls who considered him a heartthrob, and the recording sold more than one million copies. He replicated the feat with the full-length album My World 2.0 (2010), which debuted at number one on the Billboard album chart. Its lead single, the yearningly heartfelt “Baby”—featuring a guest Canadian singer, songwriter, and guitarist best known for the global pop phenomenon “Call Me Maybe,” which became the biggest-selling song in the world in 2012 and the best-selling domestic Canadian single in history.
