According to a posting AllMetallica.com, Metallica's Kirk Hammett and Lars Ulrich were spotted at The Mars Volta show at the UC Berkeley Amphitheatre in California on June 3.
Mars Volta is often described as a thrashing, hypnotic, hallucinatory sprawl of prog-rock and they just released their second album "Frances the Mute". Mars Volta will tour with System of a Down later this summer.
