This song by Black Sabbath is consistently ranked as one of the greatest heavy metal songs of all time. Maybe the biggest hit of Ozzy’s group, along with “Iron Man.”

The lyrics were written by and about bassist Geezer Butler, whom the band often called paranoid, even though he didn’t know what the word meant. They are about Butler’s feelings as a depressed teenager and him thinking he was going insane.

According to the band, the song only took 20 minutes to write. It was supposed to be just a filler song and the album was supposed to be called War Pigs. When they released it as a single and it got very popular, however, the record label wanted them to name the album Paranoid.