Olly Murs' stint on X Factor launched his pop-star career, but his limber voice and cheeky attitude made him a supernova. His biggest hits have been radio staples around the world, while digging deeper into his catalogue reveals brassy dance tracks like "Did You Miss Me?" and bummed-out shuffles like "Grow Up"—as well as Robbie Williams, who lays down a jazzed-up Disney duet with his fellow Brit.