On the day of the Atlanta show, Hetfield was reportedly unable to get out of bed even after receiving several cortisone shots in his back.

The three shows went on without Hetfield and fans were treated to the vocal stylings of several guest singers as other bands on the festival tour pitched in to front the heavy metal outfit.

Korn’s Jonathan Davis, System Of A Down’s Serj Tankian, Kid Rock, and his sidekick, Joe C did their part, singing from lyric sheets printed out by the band. Metallica bassist Jason Newsted also took the mic for a few numbers.

Metallica’s tour schedule remains intact, with the next date set for July 12 at Denver’s Mile High Stadium. The band is going to revisit the markets where Hetfield couldn’t perform and play free shows for those who held onto their ticket stubs.

Tickets from the Sparta gig will be honored August 2 at Buckeye Lake in Columbus, Ohio; Atlanta fans can get in free August 4 at the Georgia Dome; and band will return to Texas Stadium in Dallas August 6.