Foo Fighters drummer Taylor Hawkins and Red Hot Chili Peppers drummer Chad Smith appear to have unheard songs from Ozzy Osbourne’s new album Patient Number 9.

“Watt enlisted two drummers on Patient Number 9: the Red Hot Chili Peppers’ Chad Smith and Foo Fighters’ Taylor Hawkins, who died unexpectedly this past March,” a Rolling Stone story explained. “Watt says there are more recordings with Hawkins, to whom Osbourne dedicated the album. ‘There’s a bunch of other stuff with Ozzy and Taylor, as well, that’s going to be used for another thing,’ the producer says.”

Billy Idol guitarist Billy Morrison said in the article about Ozzy’s musicianship. “Ozzy will sit and listen to a piece of music and he’ll point out a fucking cowbell that no one else has heard,” Morrison said. “And he’ll go, ‘That cowbell’s too loud.’ Or he’ll say, ‘There’s something up with the bass in the verse. And upon looking at it, the frequency’s wrong or some shit like that.’ He has an ear that hears everything. It’s really incredible. And I’ve got to tell you, having recorded songs with him, it’s mind-blowing.”

Foo Fighters recently held a Taylor Hawkins Tribute Concert in London, and will hold a second show later this month in Los Angeles.