Many thanks to
Dick Umbrage, who recommended
Can't Stop Won't Stop: A History of the Hip-Hop Generation by Jeff Chang to me. It's a great read, tracing the development of hip-hop from its beginnings as a teenage fad confined to a seven-square-mile area of the Bronx to its present status as an international cultural - and marketing - phenomenon.
Chang's talked to Kool Herc and Talib Kweli and everyone in between. Best of all, he connects the development of the different waves of hip-hop to specific developments in specific cities. He starts with the building of the Cross-Bronx Expressway in the 1950's, pointing out how it destroyed tremendous amounts of housing in the Bronx and started a trend that pushed white families into the suburbs and many black families into the projects. He talks about the transition in West Coast rap from NWA's anger to Snoop Dogg's chill, and traces the change to the groundbreaking L.A. gang truce in 1992.
It's a great lens for him to look at America's cities and at the massive consolidation of the media. If there's a down side, it's his tendency to jump back and forward a bit in the timeline without always making it clear what year he's talking about. And, of course, a history of hip-hop can't do everything - he touches on the misogyny that seems so ingrained in hip-hop without really delving into the causes or effects, for example. And he doesn't get into rap homophobia at all (he does dig into both rap anti-Semitism and black-Korean relationships, however).
In short: read it. You'll like it. And you'll learn some stuff, too.