Led Zeppelin: Stairway To Heaven
It's been alleged that if you play Stairway To Heaven backwards, around where Plant sings "if there's a bustle in your hedgerow", you'll hear: "Oh here's to my sweet Satan. The one whose little path would make me sad, whose power is Satan. He will give those with him 666. There was a little toolshed where he made us suffer, sad Satan." Robert Plant unsurprisingly slated the claims as "ridiculous".
