The Roots perform on 'Late Night with Jimmy Fallon,' March 2011. Photo: Jason Kempin

No exception to the talk show promo circuit, “Weird Al” Yankovic swung by Late Night with Jimmy Fallon last night to promote Alpocalypse, his first album release in five years. Yankovic brought his trusty accordion and nimble fingers along, performing “Beer Barrel Polka” alongside the Roots to cap off the program. Drummer Questlove, ever aware that crafty accordion-istas with a deft for improv are few and far between, took advantage of having Al around to cover Madvillain‘s “Accordion” from the seminal underground album Madvillainy. Feeling giddy during this historic moment (and reaching 1.6 million followers on Twitter), the Roots’ ringleader recorded this off-camera jam session and promptly shared it. The result is a playful, completely unexpected cover of a hip hop classic. [Stream here via Swift.fm]