Believe it or not, the song "Stairway to Heaven" is 50 years old. Led Zeppelin first played it in public in March of 1971, and the recording was released on their fourth album in November of that year. The song quickly became a prog-rock favorite but eventually was overplayed. As it was discovered by succeeding generations, that cycle continued over and over again for 50 years -so far. You could say that "Stairway" has everything -a ballad at one end and a rocking climax at the other, the hipness of a permanent album cut, a killer guitar solo, and lyrics that were just confusing enough to act as a Rorschach test: everyone interpreted them in their own way.
What if the lyrics to “Stairway” are so strange and convoluted because they’re actually meant to be played backwards? That was the theory of televangelist Paul Crouch, who decided in 1982 that the verse beginning around 4:19 (“If there’s a bustle …") offers a satanic message when played in reverse. This, according to Crouch, is the hidden message: “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 tool shed where he made us suffer, sad Satan.” In the book Hammer of the Gods, one of Zeppelin’s recording engineers offers this rebuttal: “Why would they want to spend so much studio time doing something so dumb?”
That's just one of 11 facts about "Stairway to Heaven" that you can read at Mental Floss. The last one makes it all worthwhile.