Watch Foo Fighters, Dave Grohl's Doctor Cover White Stripes

After "Seven Nation Army," band also brings out Godsmack's Sully Erna for Alice Cooper cover at Boston show

Foo Fighters wrapped up the July leg of their stadium-filling "Throne" tour Sunday night with a second show at Boston's Fenway Park, where the band paid homage to the man who practically made this trek possible: Dave Grohl's orthopedic surgeon. Midway through Foo Fighters' set, Grohl invited Dr. Lew C. Schon, who helped the rocker after Grohl seriously injured his leg in Sweden, onstage to lead the band in a spirited rendition of White Stripes' "Seven Nation Army."

"Holy shit, that's actually my doctor," Grohl said after the cover as the crowd chanted "Lewwww." "What a badass." After the Foo Fighters' kicked off their most recent North American trek with an all-star 20th anniversary celebration in Washington, D.C., subsequent shows have seen the band welcome surprise guests like Red Hot Chili Peppers drummer Chad Smith and members of Bad Brains to the stage, as well as one lucky 18-year-old celebrating a birthday.

On top of "Seven Nation Army," Foo Fighters also covered Alice Cooper's "School's Out." The group has played the 1972 single roughly a dozen times over the past five years, either as a full performance or snippet during band introductions. Sunday's version, however, stood out with a guest appearance by Godsmack singer (and Massachusetts native) Sully Erna on lead vocals.

After a quick trip to Japan and South Korea, Foo Fighters will return to North America for two more months of shows kicking off August 12th in Edmonton, Alberta. It's unclear whether Grohl's massive throne will still be needed for the band's next jaunt.

"I'm starting to do a little bit of rehab exercise and the cast is off," Grohl told Rolling Stone of his road to recovery. "The swelling's down. The pain's gone. It's just a matter of getting those kick-drum muscles back, man. I can't fuckin' lose those. That's important to me. So I'm sitting here, moving it around, doing my exercise as we speak. So it's OK."