Tonight (April 12), Slayer’s Kerry King and Dave Lombardo, Anthrax’s Charlie Benante and Frank Bello, Megadeth’s David Ellefson, and Adrenaline Mob’s Mike Portnoy will be taking part in the third Metal Masters Clinic at the Key Club in Hollywood, CA. However, rumors have started to gain steam that none other than Philip Anselmo and Geezer Butler will be performing at tonight’s event.

As you may remember, the Down/Pantera frontman made a “surprise” appearance at the second Metal Masters Clinic in NYC last September. Anselmo joined the musicians onstage to perform Pantera’s “A New Level” and “Fucking Hostile.” On the other hand, this would mark the Black Sabbath bassist’s first Metal Master Clinic appearance.

While it’s safe to assume these rumors are indeed true, we’ll have to wait till tonight to find out for certain. In case you happen to be in the Hollywood area with no plans tonight, tickets for the Metal Masters Clinic (which will also feature a performance from Adrenaline Mob) are still available for purchase.

Update: No longer a rumor! Video of Anselmo and Butler performing at the Metal Masters Clinic can be seen here.