A version of this song from Black Sabbath's first demo exists on the Ozzy Osbourne compilation album "The Ozzman Cometh". The song has an extra verse with additional vocals before the bridge. The guitar and bass are tuned down one whole step, resulting in the key position of A being played on the fretboard, but having the pitch as G (octave - D flat) to the listener. It's one of the band's most frequently performed tracks, being featured on every single tour of their career.