James Hetfield's oldest daughter Cali joined him on stage at the second annual Acoustic-4-A-Cure concert, but it wasn't to reimagine your favorite Metallica song. Watch, instead, as they collaborate on a touching version of Adele's "Crazy for You" in the above video.

Other special guests for this year's Acoustic-4-A-Cure, co-hosted by Sammy Hagar and Hetfield, included Joe Satriani and Chad Smith -- both members of Chickenfoot with Hagar -- as well as Jerry Cantrell, Linda Perry and Pat Monahan of Train, among others.

Perry and Satriani joined together for a take on Led Zeppelin's "Communication Breakdown." She also sang a cover Jefferson Airpline's "Somebody to Love" with Hagar. Cantrell, of Alice in Chains fame, joined Hetfield for a mournful new take on Blue Oyster Cult's "(Don't Fear) The Reaper," attached below.

Watch Jerry Cantrell join James Hetfield for '(Don't Fear) The Reaper'

The Acoustic-4-A-Cure, held Friday (May 15) at the Masonic in San Francisco, benefits the Pediatric Cancer Program at the University of California at San Francisco's Benioff Children's Hospital. Hagar has credited Neil Young's long-running Bridge School benefit series with inspiring him to launch his own charity concert.

Hagar actually brought Cali out to the stage, jokingly giving her a final shove toward the microphone. "Say hi to my beautiful daughter," Hetfield said, before beginning a well-received collaboration with the 16 year old.

Oh, and Hetfield clearly knows the words. Trust us, that tends to happen with Adele's music when you have daughters.

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