Yes, yes, y’all. On last night’s Late Night With Jimmy Fallon, Fallon and guest Justin Timberlake busted out “History Of Rap 2,” the companion piece to last year’s rapid-fire medley of all things hip-hop. The sequel includes OutKast, auto-tune, “The Dougie” and Biz Markie. It’s kind of funny to see — two white dudes teaching the world rap history (with the expert help of backing band The Roots). But these two MCs are more than up to the job.