Black Sabbath's Iron Man was also covered on the album: Nativity in Black: A Tribute to Black Sabbath. Strangely, for a cover, the lyrics are 're-sung' by Ozzy Osbourne, the difference being the band itself. In this case, Therapy? are backing Ozzy up. I'd say this version sounds heavier than the original - heavy as Black Sabbath were at the time, they can sound quite thin when listened to today. (Still awesome of course)