For the next 26 years, I avoided rap music the way you step over a crack in the pavement. I heard it booming out of cars and alleyways from Paris to Abidjan, but I never listened. In doing so, I missed the most important cultural event in my lifetime. No American music has exploded across the world with such force since swing jazz in the 1930s. This defiant culture of song, graffiti, and dance, collectively known as hip-hop,has permanated almost every society.