Although most of the album is in the band's trademark heavy style, some songs demonstrate a more sensitive approach. "Changes", for example, written by Iommi with lyrics by Butler, is a piano ballad with mellotron. Iommi taught himself to play the piano after finding one in the ballroom of the Bel-Air mansion they were renting. It was on this piano that "Changes" was composed. "Tony just sat down at the piano and came up with this beautiful riff," Osbourne writes in his memoir. "I hummed a melody over the top, and Geezer wrote these heartbreaking lyrics about the break-up Bill was going through with his wife. I thought that was brilliant from the moment we recorded it."