Wolfgang Van Halen was one of dozens of artists who were slated to perform at Black Sabbath and Ozzy Osbourne's "Back to the Beginning" farewell show next week, but in a recent interview the son of Eddie Van Halen revealed that he had to drop out of the event due to a scheduling conflict with his band Mammoth.

"I, unfortunately, had to back out because the Creed tour starts the day after, and I [wouldn't] be able to pull it off — unfortunately," he explained (Mammoth is playing support on that tour. "I'm very excited to watch it, but I unfortunately had to back out."

With the show less than two weeks away, Black Sabbath shared a glimpse into their rehearsals on Tuesday (June 24). Back to the Beginning is set to go down July 5 at Villa Park in Birmingham, England. Metallica, Guns N' Roses, Slayer, Pantera, Gojira, Halestorm, Alice in Chains, Lamb of God, Mastodon, Anthrax, TOOL and Rival Sons will also be playing sets, along with solo performers.

Although he's unable to help celebrate Ozzy's final performance, Wolfgang did recently help induct him into the Rock & Roll Hall of Fame last year.

"My family lineage is intertwined and has gone way back with the likes of Ozzy," he said in an interview last month. "My dad was very, very close with Tony [Iommi], probably the closest of any other guitar players out there. It was a crazy honor to be there for the Hall of Fame induction."

Klinger