Prince's 1984 album Purple Rain made him a superstar, and among its many hits, there's the controversial track, "Darling Nikki." The song's explicit lyrics about sex stirred quite a controversy, prompting Tipper Gore to start the Parents Music Resource Center, which led to those Parental Advisory stickers on albums. But there's a twist: the song has a hidden message that's actually Christian, about the apocalypse, and you can only hear it when played backward.
"Hello, how are you? I'm fine. 'cause I know
That the Lord is coming soon, coming, coming soon.