The Roots' foray into becoming the coolest band in late night television began in March of 2009, when the Illadelphians signed on as the musical backbone of Jimmy Fallon's Late Night program. And in the nearly five years since, the group took Fallon from being the goofy, inoffensive and awkward SNL alum into one of the strongest entertainers in the business, largely due to The Roots' innovative and free-wheeling take on the old, established model. As the platform for a number of running sketches—Slow Jamming The News, Freestyling With The Roots—as well as the house band for any musical guests that came through, The Roots gave Fallon early breathing room by being entertaining and diverse, and grew with him into a full-on comedic and functional team.

So when it was announced last April that Fallon would be taking over Jay Leno's seat at the venerable Tonight Show—with the new show's first episode set to air tonight (Feb. 17)—it was natural that he would take The Roots with him to one of the most high-profile slots in late night. As the new show gets set to kick off, XXL takes a look back at some of The Roots' best musical contributions to the show, from Slow Jamming The News with Barack Obama to contributing to one of the greatest versions of Kanye West's "Bound 2" that has ever existed. Wise up. —Dan Rys (@danrys)