Justin Timberlake and Jimmy Fallon on Late Night with Jimmy Fallon
Lloyd Bishop/NBC

Jimmy Fallon and Justin Timberlake performed their history of hip-hop last night on Late Night With Jimmy Fallon.

On last night's Late Night With Jimmy Fallon, Justin Timberlake (who's terrific in The Social Network, which opens tomorrow) did a three-minute "history of hip-hop" that, while extremely silly, is highly instructive if you're curious about why both of these guys have a lot of fans. Simply put, they're having a fantastic time, and there's no pretentiousness in it, and it's accompanied by The Roots — who continue to be Fallon's greatest asset.

Between this and the opening of the Emmys, Jimmy Fallon is fast becoming a veritable ambassador for good-natured, non-snarky, entirely joy-fueled entertainment — a niche that sorely needs filling.