Iron Man - Live at Portland Memorial Coliseum, Portland, OR, 4/22/1982

This song is about a man who travels through time and sees the end of the world. On his way back to Earth to warn the human race, he goes through a magnetic storm and is turned to iron. Nobody believes him about the end of the world and he gets mad, taking his rage out on the human race, thus bringing about the end of the world that he saw. Sabbath bassist and lyricist Geezer Butler explained in NME that after Ozzy Osbourne put the idea in his head: "I was walking down the street one day and thought... 'what if there were a bloody great bloke made out of metal walking about?'"

Fittingly, "Iron Man" is a landmark in the heavy metal genre, with a massive guitar riff and a sci-fi, apocalyptic lyric. Black Sabbath influenced pretty much every metal band that followed, especially British acts like Iron Maiden, Saxon, and Judas Priest.

Sabbath guitarist Tony Iommi came up with the guitar riff in the studio when drummer Bill Ward started playing the big, foreboding bass drum beat. Iommi created a wash of sound by bending his string, which is where Ozzy's "I am Iron Man vocal comes in." Then he blasted into the riff. "Most of the riffs I've done I've come up with on the spot, and that was one of them," he said in a Songfacts interview. "It just came up. It went with the drum, what Bill was playing. I just saw this thing in my mind of someone creeping up on you, and it just sounded like the riff. In my head I could hear it as a monster, so I came up with that riff there and then."