Jessie J

She clawed her way to the top doing behind-the-scenes work, but Britain's Jessie J has "spotlight" written all over her. Fierce, funny, blessed with serious vocal chops and an even more serious diva presence, the young lady born Jessica Cornish paid her dues early on by, first, inking a record deal to a label (Gut Records) that went belly up and, later, penning songs for the likes of Justin Timberlake, Christina Aguilera, Chris Brown and Miley Cyrus. Along the way, she also had suffered a stroke at the age of 18 -- an experience that, along with other health problems, not only fueled her desire to become a pop star, but also inspired her songwriting. Finally, she signed a deal with Universal, which put out her first single. "Do It Like a Dude" helped establish Jessie's style: a genre-jumping mix of club-ready hip-pop (with a pinch of dancehall) and rock attitude, paired with clever, cutting lyrics. The song rose to No. 2 on the U.K. charts and, along with her B.O.B.-featuring second single "Price Tag," started earning Jessie buzz in the U.S. Her full-length debut dropped in 2011.