Late 1970s New York City was bankrupt and its streets dirty and dangerous. But thecity had a wild, raw energy that made it the crucible for the birth of rap culture and graffiti. Graffiti writers worked in extremely tough conditions: uncollected garbage, darkness, cramped spaces, and the constant threat of police raids, assault by security staff and attacks by rival crews. It was not unlike practicing performance art in a war zone. Yet during the...