I caught this great segment on Jimmy Fallon the other night live looping with Robert Plant! Click here to watch the video. I really enjoy how Fallon just goes for it with legends like Plant and attempts things like this.
The Tonight Show Starring Jimmy FallonJimmy Fallon & Robert Plant Form 2-Man Doo-Wop Group Using iPad AppJimmy and Robert Plant loop their voices on an iPad app to form a 2-man doo-wop group -- singing the classic song "Duke of Earl" by Gene Chandler.
They are using the iPad app Loopy http://loopyapp.com/.