Last week, Dave Grohl and Taylor Hawkins joined Conan O’Brien for a little chat, then followed it up with a raucous closing performance of “Walk”. One week later, aka last night, Foo Fighters returned to Stage 15 on the Warner Bros. lot to roll out “Dear Rosemary”. They weren’t alone, either. Joining the fearsome five was Hüsker Dü legend Bob Mould. What can we say? It sounded like the Wasting Light track to a T. Nonetheless, an amicable surprise, though what gives, Bob? No reading to go with it? We kid. Check it out below, courtesy of The Audio Perv.