Just when I thought our Italian friend with the linen over his keyboard was unique, I find this guy using a sheet over his PA keyboard and a blindfold.
Having tried a dish towel over one of my CBA keyboards I can assure you that it makes it no more difficult to play than without it. I've never played with a blindfold, but I'm not going to try. Friend of mine did that, stepped on one of his kid's rollerskates, and put his head through a glass display cabinet!
Player believed to be German somewhere in California at a Bierfest. https://www.youtube.com/watch?v=Wne2zZowMIU