Time was, great hip-hop was self-evident. With few exceptions, the best rap albums of the '80s were also the most widely celebrated, and everybody knew a classic when they heard it. Then things got messy: The '90s saw the rise and fall of a bitter bicoastal war, which gave way to an explosion of regional styles. These days, you need an atlas to keep up: Detroit succumbed to some well-known wiggers and a phenomenon known as acid rap, Mannie Fresh and Master P took over New Orleans with revamped electro beats, San Francisco embraced alt-rap MCs and turntablists, Bone Thugs-N-Harmony put Cleveland on the map by singing rap lyrics instead of speaking them. . . . On it goes, a constantly shifting labyrinth of... More >>>