Hip-hop has come a long way from its origins in the Bronx in the 1970s, when rapping and DJing were just part of a lively, decidedly local scene that also venerated b-boying and graffiti. Now hip-hop is a global phenomenon and, in the United States, a massively successful corporate enterprise predominantly controlled and consumed by whites while the most prominent performers are black. How does this shift in racial dynamics affect our understanding...