When you get this many musicians in one place, impromptu jam sessions are bound to happen! Earlier today (Aug. 7) at the backstage Billboard Lollapalooza lounge, viral stars Karmin -- the YouTube duo known for its fast-talking female rapper on "Super Bass" and "Look At Me Now" covers -- got a drop-in from one very special guest.
Skylar Grey, guest vocalist on Dr. Dre  and Eminem 's "I Need a Doctor" (among other tracks), was nearby while Karmin's cover of the track was being recorded. So naturally, Skylar decided to give the take on "I Need A Doctor" an authentic addition. Watch below, as Skylar and Karmin rock the rap track on the fly. Only at Lolla!
- Live