Youtuber Evan Petrone sez:
This is me playing the piano backwards. Yes, I know this is splattered with wrong notes and edits, it’s more meant to showcase the trick rather than exhibit musical talent. I can’t reach the pedals with my legs backwards, so that kind of ruins the song a bit. Trust me, I’m much better when I’m actually facing the keys.
If you’re wondering how I actually go about doing this, I have a genetic ligament-loosening disorder called Ehlers-Danlos Syndrome (Hypermobility Type). I have loose ligaments and hypermobile joints, which allows me to rotrate my shoulders out of socket and play the piano backwards like this. Enjoy.