James Hetfield showed up to perform at the annual Acoustic-4-A-Cure benefit in San Francisco last night, giving an old Metallica number a whole new sound in the bargain. As you can see in the fan-shot footage above, Hetfield's set included an acoustic rendition of "Motorbreath," a song that first appeared on Metallica's 1983 album Kill 'Em All. After opening with "Motorbreath," Hetfield went on to perform Metallica's "The Unforgiven" and a cover of the Screamin' Jay Hawkins classic "I Put a Spell on You."

The show, held at the Fillmore in San Francisco, marked the third annual event headlined by Hetfield and Sammy Hagar to help raise funds for the Pediatric Cancer Program at UCSF Benioff Children’s Hospital. Previous Acoustic-4-A-Cure performances have included appearances from Nancy Wilson of Heart, Jerry Cantrell of Alice in Chains, Chad Smith of the Red Hot Chili Peppers and Billie Joe Armstrong of Green Day.

Hetfield and Hagar were joined on this year's bill by a diverse group of performers led by Joe Satriani, Melissa Etheridge, John Mayer, Train frontman Pat Monahan (out of frame), longtime Hagar bandmate Vic Johnson and Kris Kristofferson — all playing unplugged in what Hagar refers to as "the best venue in the world."

"If you write a check, it’s fine, but you don’t feel anything. I prefer to donate my time," he told SF Gate. "You go there, and you play music, and your fans pay to see you. You take the money, and you give it to this thing. There’s no silent auction. We’re not going to show you pictures of babies dying. We’re not going to have doctors up there giving you these big long speeches that bum you out. It’s a f---ing concert. Just come and enjoy the show."

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