Stairway to Heaven

"This is rumored to contain backward satanic messages, as if Led Zeppelin sold their souls to the devil in exchange for "Stairway To Heaven." Supporting this theory is the fact that Jimmy Page bought Aleister Crowley's house in Scotland, which had become a well known Satanic church and was known as "The Toolhouse." In his books, Crowley advocated that his followers learn to read and speak backwards."
Songfacts.