Reformed rock legends Black Sabbath stayed focused on completing their first studio album in 35 years by steering clear of booze and drugs.

Ozzy Osbourne, Bill Ward, Tony Iommi and Geezer Butler reunited in 2011 and plan to hit the road for a world tour in April (13).

They have been in the studio creating tracks for a new disc, which has a working title of 13, and Butler insists it is the band's most professional album to date because none of them were drunk or high during the recording process.

He tells Blabbermouth.net, "This is the first time we've done an album together sober; none of us have been drinking or doing drugs or anything, so it's been more professional in that way. And we've stuck to a schedule every day. We'd go in at one o'clock and finish at six, just to keep everything fresh. Five hours a day, that's it."

Butler also reveals Osbourne is recovering well after burning himself while trying to put out a blaze at his home in California earlier this month (Jan13).

The bassist adds, "He's doing alright. He burnt his hand when he was putting the fire out. He's got it in a plaster cast."