The Gap has confirmed signing Grammy-winning singer Joss Stone to appear in its summer ad campaign. The 17-year-old follows in the footsteps of Sex and the City star Sarah Jessica Parker, whose three-year contract with the company has expired, according to a Gap statement. Stone will appear and sing in ads promoting white denim. Financial terms were not disclosed. Independent Laird + Partners in New York handles the account. The client spends about $120 million annually.