Timbaland and singers Dev and Iyaz will also appear on the 15-song set, which drops on September 20. By James Dinh Demi Lovato Photo: Kevin Mazur/WireImage Demi Lovato wasn’t kidding when she teased some star-studded collaborations for her comeback album Unbroken. On Tuesday, the Disney star revealed on her website that her upcoming set (due September 20) will include musical pairings with Missy Elliott, Timbaland, Jason Der
