Back in the 1970s there were a lot of claims that rock-n-roll was evil because it allegedly contained backwards masked messages. Basically the claim was that music contained voice messages recorded backwards and hidden in songs that would subconsciously find their way into your brain and virally infect America's youth thus leading to the breakdown of society as we know it... or something like that. Well this fellow, Jeroen Offerman, was inspired enough by this to spend 3 months learning the classic rock-n-roll song Stairway to Heaven backwards. He recorded himself singing it backwards with a reversed Karaoke track, then reversed the whole thing and the result is the video you see above.
Very impressive Jeroen, but seriously dude, you have too much time on your hands.