Many listeners probably assumed that the title track from Iron Maiden's Seventh Son of a Seventh Son was referring to Willie Dixon's proto-rock classic, or maybe the Seven Deadly Sins. But, as a sea of hype for the Ender's Game movie has reminded me, "Seventh Son of a Seventh Son" was inspired by an Orson Scott Card novel.
Card's Alvin Maker series is not as popular as his Ender series, but it exemplifies his knack for combining folklore and fantasy. It's no wonder that Steve Harris, one of metal's most literary-minded songwriters, took to Seventh Son, Card's book about a boy who hangs out with William Blake. The lyrics to "Seventh Son of a Seventh Son" aren't going to get anyone out of a book report, but along with the music they'll quench your sci fi/fantasy metal needs.