In a Classic Tales animated video, Trujillo recalls how he was working in a studio with Mike Muir on their first Infectious Grooves album while the Prince of Darkness was in the room next door.

"One night we heard this loud, English growl," he explains. "All I see is Ozzy's cowboy boots dangling in the hallway. He'd tackled the bass player's girlfriend and he'd bit into her cowboy boot, and she was pissed.

"I thought, 'This is my hero, tackling woman, biting through their boot... how rock'n'roll is that?'" Trujillo asked Osbourne to record guest vocals on Infectious Grooves track Therapy. He eventually agreed, and even created his own dance routine for the song. Then he invited the Grooves on tour with him.

After they'd played their support slot, the bassist remembers, "We were creeping around backstage in the dark. I wound up tripping over a mound of cable and I knocked out the power. We get up and ran to catering.