As more and more superstar acts are born inside laptop-lit bedrooms, Dave Grohl remains the face of that old-fangled tradition of picking up an instrument, practicing it till your fingers bleed, then heading out on the open road in a beat-up van to share your songs with the world. The former Nirvana drummer and Foo Fighters frontman, 52, has captured that experience in What Drives Us, his new doc featuring Ringo Starr, St.