In a small room, Hetfield recounted tales of his first guitar, becoming a musician, rising to fame, and he played a few riffs during the session. In the meantime, customers continued to shop in the store, having no idea it was Metallica's frontman playing.

This Friday, May 16, Metallica will team up with the Major League Baseball's San Francisco Giants for the 2nd annual Metallica Night at AT&T Park.