Ben Harper is a shape-shifter, moving through genres with uncanny ease. Starting out as a gospel blues folk hybrid, Harper has branched out to include rock, funk, reggae, soul and country into his beguiling sound. Adopted by the jamband circuit, while also being courted by mainstream radio and heralded by roots enthusiasts, Harper’s rabid fanbase is as broad as his tastes. His newest album, Diamonds On the Inside, is his fifth to date, and its songs display a healthy surge in maturit...