Cheeky Swedish PopRocksters The Wannadies released their album Bagsy Me in 1996. It's quite good some would say. Tracks 7.Silent People and 10.Bumble Bee Boy are melodically (same tune) the same but at different speeds and different lyrics.

Not very amazing I hear you cry!

OK, but try this. Put the CD in a player and press play. Upon playing, search backwards, to before track 1 and you should discover, what would appear to be demo versions of both songs! At the same time!!

Silent People comes from the left channel and Bumble Bee Boy comes from the right.

Nice!