Not too long ago, Dave Grohl fell while onstage, broke his leg, and still came back out to finish performing. Since then, Grohl has been performing on a specially made throne of guitars, and at Sunday night’s show at Boston’s Fenway Park he had a very special guest come out to help Foo Fighters cover The White Stripes.

It wasn’t any of the high profile music world guests that have joined them at previous shows, instead it was Dr. Lew Schon, the orthopedic surgeon who helped Grohl with his broken leg. As it turns out, Dr. Schon is a pretty awesome frontman, covering “Seven Nation Army” with aplomb.

As Dave Grohl himself says “Holy shit, that’s actually my doctor, what a badass.” Watch footage above and another angle below.