Run-DMC will headline Hip Hop 50 Live — a star-studded extravaganza celebrating the golden anniversary of the music and the culture — at Yankee Stadium on Friday. Taking it back to the Bronx, it’s a who’s who featuring everyone from OG groundbreakers (Slick Rick, the Sugarhill Gang) and ’90s icons (Nas, Ice Cube) to 21st-century titans (Lil Wayne, T.I.).