NEW YORK, NY - MARCH 11: Justin Timberlake visits "Late Night With Jimmy Fallon" at Rockefeller Center on March 11, 2013 in N
Theo Wargo

Every single night of Justin Timberlake's residency on Late Night With Jimmy Fallon has been bananas. The "Suit & Tie" singer served as musical guest (and Fallon sidekick) to promote The 20/20 Experience, which officially drops March 19.

JT used his late night gig wisely, first by ending his non-feud with Kanye West, then by joining a barbershop quintet and singing alongside Michael McDonald (while impersonating Michael McDonald). If you watched the show all week long like we did surely you thought how can JT and Fallon possibly top their rendition of Toto’s “Africa?

Well, the triple-threaters hit it out of the ball park last night. JT and Fallon wrapped up their week-long bromance by launching into the "History of Rap Vo. 4"! Check out their rapping medley below.