Jack Black + Kid Band Cover Ozzy Osbourne at 100th Birthday Party for Tom Morello’s Mom

At the 100th birthday party for Mary Morello, mother of Rage Against the Machine guitarist Tom Morello, actor and Tenacious D frontman Jack Black joined a kid band to perform a cover of Ozzy Osbourne's chilling hit "Mr. Crowley."

Morello shared a nearly eight-minute video on Instagram, calling the performance a "stirring rendition" of the Blizzard of Ozz classic. It appears mom quite enjoyed it as well as her son notes, "Mary was pleased!"

Perhaps that's because Tom's son/Mary's grandson Roman was on guitar!

Morello shouted out the members of the band, which features 12 and 13-year-old musicians, including the aforementioned Roman, as well as Yoyoko Soma (a Japanese drummer who has garnered internet fame), Roya Feiz (bass) and Hugo Weiss (keyboard).

READ MORE: Watch Tom Morello's Mom Introduce Rage Against the Machine as 'Best F--king Band in the Universe' in 1996

Black's nasal-toned voice is perfectly suited for the Ozzy cover and the youngster band clearly has quite a lot of talent, drawing parallels to the 2003 hit movie School of Rock, where Black's character Dewey Finn inspires a group of young students to learn their instruments and rock out.

Watch the performance below.

From all of us at Loudwire, we wish Mary Morello a very happy 100th birthday!!!

Jack Black + Kid Band Cover Ozzy Osbourne's "Mr. Crowley" at 100th Birthday Party For Tom Morello's Mom Mary