Jack Black, along with a group of talented 12 and 13 year olds, covered Ozzy Osbourne's "Mr. Crowley" at Tom Morello's Mom's 100th birthday party. Yep, you read that sentence right. There's a lot to unpack, but it's all amazing.

The Tenacious D frontman led the band on vocals, giving his best Ozzy impersonation. Tom's son Roman Morello played guitar and showed off his skills with some pretty impressive solos and playing the guitar behind his back.

The Rage Against The Machine guitarist shared a video of the performance on Instagram, writing: "Mary Morello’s 100th bday celebration featured a stirring rendition of @ozzyosbourne & #RandyRhoads “Mr. Crowley” performed by @jackblack and a kick a** band of 12 & 13 year olds! Mary was pleased!" The young drummer, Yoyoka, also shared the video on YouTube, which you can watch above.

Mary Morello turned 100 on October 1. Tom has always spoke highly of his mother, who's been an activist all her life. He's shared fascinating stories about his mom over the years. On her 97th birthday, Tom highlighted some of her accomplishments:

"In the 1930s she helped feed hobos during the Great Depression and supported the coal miners struggle to organize. In the 1940s she helped raise war bonds to defeat the fascists in WWII. In the 1950s she taught international students and opposed racist Jim Crow laws and as a single woman she’s traveled to over 60 countries. In the 1960s she aided anti-colonial movements while living in Africa. In the 1970s she was a radical teacher in a conservative high school inspiring students to challenge the system, and aided the United Farm Workers and the Urban League. In the 1980s she went on nine peace missions to the Soviet Union and Cuba. In the 1990s she opposed the first Iraq War and founded an international organization to oppose music censorship called Parents For Rock and Rap. In the 2000s she helped homeless people and recovering addicts get their high school diplomas at the Salvation Army and opposed wars for oil. In the 2010s she volunteered at local soup kitchens and currently works with Doctors Without Borders and Mideast peace organizations, still feverishly writing letters to the editor, all the while being a loving grandparent."