Age: 24
Before the English singer-songwriter took center stage with her own hit “Do It Like a Dude,” she gained notoriety for her covers on YouTube and for penning Miley Cyrus’ biggest single to date, “Party in the U.S.A.” Nowadays, Jessie J is a pop star in her own right, with her latest single “Domino” peaking at number six on on the Billboard Hot 100 and becoming a number one hit in the UK.