This had to happen. Mardi Gras Indian music is one of the few remaining signifiers of New Orleans culture. So is hip-hop, from its national heroes to its local strain of bounce. The songs and chants of Mardi Gras Indian chiefs bear remarkable similarities to the flow and even content of boasting and toasting rappers. Young Indians have been slowly integrating rap style into their performances for years now, but the tradition, now spanning three centuries, has r...