California-bred Ben Harper started out in the early '90s as a jam-band bard buoyed by a breezy strum and some righteous indignation. Though Harper's roots are planted in the earthy aesthetic and political ethos of blues and folk music, he's applied his mellow voice and ace musicianship to an expansive palette over time, dabbling in jazz and hip-hop (1999's Burn to Shine), scorching gospel (2004's There Will Be a Light) and Southern rock (2009's White Lies for Dark Times). But as the musical magpie has stretched his wings, his social conscience remains at the heart of his songs.