This is what pure entertainment looks like: two white dudes rapping and dancing their hearts out. Justin Timberlake and Jimmy Fallon performed their third "History of Rap" with The Roots providing instrumentals to a mix that started with Run DMC and ended with Nicki Minaj. While it's essentially like watching four minutes of really well-rehearsed karaoke, it takes talent to pull the whole thing off. Enjoy the video below from tonight's show.