Black Sabbath singer Ozzy Osbourne was asked by Spin.com why the band's current touring drummer, Tommy Clufetos, did not record the drum tracks on Sabbath's newly released studio set, 13, on which the drums were played by Brad Wilk of Rage Against The Machine. Ozzy replied, "The way it was dealt with was wrong, because you can't keep people waiting for nothing. We were going to use Tommy at the beginning, and Rick (Rubin, producer) was against it. And then it turned out that it wasn't dealt with professionally and I got a bit pissed off. Anyway, Tommy's doing a great job on the road with Sabbath."

Asked what happened with original drummer Bill Ward, who was announced as part of the band's reunion in late 2011 but bowed out a few months later, Ozzy told Spin, "To be absolutely truthful with you, I can't really remember. It was such a long time ago. There was the business side of it and the money side of it. We just didn't have the time to keep the people waiting another f***ing ten years . . . We would have loved Bill Ward to step up to the plate, but it never worked out."

Ward claimed that he sat out the reunion because of unfair contractual terms, although the members of Sabbath have hinted in other interviews that he wasn't physically up to the task.

13 is the first album in 35 years to feature Butler, singer Ozzy Osbourne and guitarist Tony Iommi all playing together.

The set, which came out on Tuesday (June 11th), is likely to sell between 120,000 and 130,000 copies in the U.S. in its first week of release, according to industry web site Hits Daily Double. That could hand Sabbath its first Number One album ever in the U.S.