Former Van Halen guitarist Sammy Hagar and Metallica frontman James Hetfield are set to team up for a special benefit concert in May (14). The veteran rocker has recruited Hetfield, along with Green Day singer Billie Joe Armstrong and guitarist Joe Satriani, for the first annual Acoustic-4-a-Cure benefit gig at the famous Fillmore venue in San Francisco, California. The all-star line-up - which also features Heart's Nancy Wilson and Train's Pat Monahan - will play an all-acoustic set, and event organisers promise fans once-in-a-lifetime duets and collaborations. Proceeds from the event will be donated to the Pediatric Cancer Program at the UCSF Benioff Children's Hospital. Hagar says, "I've seen firsthand the great work they're doing and how vital community support is. I ran the idea of a benefit concert by James, and we quickly had an amazing lineup of artists on board."