"Underground" is one of those tantalizingly vague terms that's always on the verge of obsolescence until some mouthy, hungry new rapper comes along and reanimates it. Whether it was being dismissed as a fad, derided as a menace to society or ascending the pop charts, there's always been a distinct way in which hip-hop has represented its underground ethos — the long-repressed reality straight from America's cities on one hand, or a new set of… more »