<P> The song 's piano melody was composed by guitarist Tony Iommi , who was experimenting with the instrument in the studio . The lyrics were by bassist Geezer Butler , and vocalist Ozzy Osbourne has referred to the song as `` heartbreaking '' . Quite different from Sabbath 's previous work , the song was described as a `` forlornly pretty '' ballad by critic Barney Hoskyns . It was inspired mainly by Bill Ward 's breakup with his first wife . </P>
what is the song changes about by black sabbath
mainly by Bill Ward 's breakup with his first wife