Last Friday (July 8), Metallica were once again joined onstage by members of Megadeth, Slayer, and Anthrax for the UK edition of the Sonisphere Festival. While they went back to performing Diamond Head’s “Am I Evil?,” a trend they changed in Germany and Italy, this time around the Big 4 brought in a special guest: Diamond Head’s Brian Tatler.

Fan filmed videos of the Big 4 playing “Am I Evil?” with the Diamond Head guitarist can be seen after the jump, while pictures of the jam (including the one up top) can be seen over at Metallica’s website. Also joining in on the fun was Exodus’ Gary Holt (who has been filling in for Slayer’s Jeff Hanneman) and Sepultura’s Andreas Kisser (who has been filling in for Anthrax’s Scott Ian).

It doesn’t come as too much of a surprise that a member of Diamond Head joined in on the Big 4 jam, especially since the NWOBHM legends were opening the UK date. Nonetheless, it’s cool to see the four bands performing with members of a band who have served as a major influence for them.

Multiple videos can be seen below:

[youtube]http://www.youtube.com/watch?v=mjJZuhvUCOI[/youtube]

[youtube]http://www.youtube.com/watch?v=qz5RJKRRnQ0[/youtube]

[youtube]http://www.youtube.com/watch?v=ekW74i05_u8[/youtube]