Yesterday (Dec. 3) was Ozzy Osbourne’s birthday and if you’ve spent any time wondering how the Prince of Darkness celebrated his 64th, all you had to do was follow him on Twitter to find out.

Ozzy posted the photo seen here of him working in the studio along with the tweet: “Spending my birthday tracking vocals on the new Black Sabbath album.”

Although various reports have speculated that several songs for the Sabbath disc have already been recorded, guitarist Tony Iommi said that’s not the case in a recent interview. On ‘The Blairing Out With Eric Blair Show’ (via Blabbermouth) Iommi cleared things up, explaining, “We’ve written 15 songs and we've played them all. But now, at the moment, we're recording them." He continued, "We recorded them at my house first, in England, just as demos, but now we're doing them for real. So we're about six tracks in now, at the moment."

Osbourne also recently went on record talking about the writing and recording process, calling it a lot of fun in comparison to their earlier years when the drugs, alcohol and egos got in the way. He talked about the music taking center stage, stating, “So what it boils down to now is the music — and that’s what got us where we are in the first place. We have come through the other side, 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.”

Ozzy certainly looks like he's having fun in the studio ... even while working on his birthday!