When DJ Kool Herc spun records at a small party in the Bronx in August of 1973, no one would have predicted his unique style would give birth to the most influential and dominant music in the world: hip-hop. In this special episode, we're celebrating the 50th anniversary of the genre by looking at how and why the music has managed to remain a local phenomenon, even as it's taken hold of the world, and what's happening in some of the country's most vibrant scenes.