While it's been years since Ozzy Osbourne has been healthy enough to travel or perform, his new album, Patient No. 9, afforded him a rare opportunity to work with some of his favorite musicians in the world, and bring two old friends back into his musical life.

Patient No. 9 is Ozzy's first collaboration with fellow Black Sabbath co-founder Tony Iommi since Sabbath's 2013 reunion album. It's also the first Ozzy LP to feature Zakk Wylde since 2007.

Wylde rejoined Ozzy's rhythm section on Patient No. 9, contributing guitars to every track, while Iommi co-wrote two songs on the album with Ozzy and producer Andrew Watt and played some lead guitar.

"It was really great working with Tony," Ozzy said during a recent Q&A. "He's the riff master. No one can touch him in that respect. I only wish we had these songs for Black Sabbath's 13 album."

While there were some years last decade where Wylde and Ozzy weren't working together, Ozzy says the guitarist provided just what his new batch of songs needed.

"Zakk is part of my family and always will be," said Ozzy. "The album needed that weight that his playing provides. He just came in and really sorted things out."

The title track, "Patient No. 9," features a solo by Jeff Beck, one of several musical icons to play on the new album.

Wylde told Metal Hammer this spring that he still can't quite believe he got to play guitar alongside so many of his heroes on this new album.

"Just to be playing on a record with Jeff Beck, Lord Iommi and Eric Clapton — if you told me when I was 15 I'd be playing on a record with three of my heroes I would have said forget about it!" Wylde said. "Oz is singing great too, so hopefully, once he's had this last surgery we can glue him back together and get him out on the road doing what he loves. That's the game plan right now."

Ozzy recently had a major spinal operation that he hopes will pave the way for him to perform again.

The frontman says working on the album was a welcome distraction from his health problems.

In an update he shared in mid-June, Ozzy said he was back home "recuperating comfortably." He will begin rehabilitation later this summer.