James Hetfield of Metallica performing at Live Earth London Concert held at Wembley Stadium. London, England - 07.07.07

The heavy rockers have been a last-minute addition to the show, which takes place in a few hours (14May08) at the Wiltern Theatre in Los Angeles.

All proceeds from the show will go to the nonprofit music school for low income students that was co-founded by Flea.

Metallica will officially kick off a summer of shows this weekend with radio festivals in Arizona and Irvine, California on Friday (16May08) and Saturday (17May08).

Source: WENN