Jimmy Fallon certainly loves his doo-wop (let’s not forget the barbershop quartet of “Ignition (Remix)†and his doo-wop duo with Billy Joel). He pulled out his trusty iPad yet again (good work, Apple!) to record a doo-wop version of the Gene Chandler classic “Duke of Earl†with Robert Plant. The Roots join in, too, at some point, and the whole thing borders on adorable.