Although the band's then-manager Patrick Meehan received credit as co-producer, Iommi said years later that Meehan had virtually no actual involvement in the album's production, saying "Meehan's ego got involved, and he stuck his name down as producer". Recording was completed at Morgan Studios in Willesden, North London in 1973. Keyboardist Rick Wakeman of the band Yes (who were recording Tales from Topographic Oceans in the next studio) was brought in as a session player, appearing on "Sabbra Cadabra".Chris Welch, Close to the Edge: The Story of Yes, pg. 141, Omnibus Press (2003), Wakeman refused payment from the band and was ultimately compensated with beer for his contribution. The members of Led Zeppelin, close friends of the band from their early days in Birmingham, showed up at the studio during Sabbath Bloody Sabbath's recording. Drummer John Bonham was eager to play on "Supernaut", but Sabbath preferred to play material other than their own for the occasion. In the end, the two bands had an improvised jam session which was recorded but never released.
