Ozzy is currently recording 15 tracks with guitarist Tony Iommi and bassist Geezer Butler but without drummer Bill Ward, who says he wasn't offered a reasonable contract to be part of the reunion.
Osbourne tells the New Zealand Herald: "Black Sabbath is very unique in the respect that nothing is formulated. It's very unpredictable. I just hope the people who have waited all these years aren't disappointed."
Ward's absence isn't the only hurdle the band have had to jump they've also had to deal with Iommi's cancer diagnosis. "It's been a bit rough on him," says the singer, "But he still manages to come up with those great riffs."
According to ClassicRockMagazine there's also an upside to Sabbath's new lease of life. Osbourne reports: "What's different now is that none of us get drunk or stoned, or any of that stuff. We're all clean and in control of ourselves. We're not intimidated by each other, there are no arguments and it's the way it should be."
It's a far cry from the out-of-control scenes which saw the band firing their frontman in 1979. "When we were kids we had egos," he says. "When you're 21 and you get some success it takes a while to get your head around.
"You have the spoils of success: cars, houses, money, drugs, groupies if you go through that and you're lucky enough to survive, you get married, you get divorced, you get married again, and it's a journey.
"But we've done it all. So what it boils down to is the music. And that's what got us where we are in the first place. We're still able to work together and that's where the enjoyment comes from. It's been a lot of fun making this record."