A piano with all the felt stripped from the hammers

I'm sitting at a concert grand in a hall I don't recognize, and when I press a key the sound is just a bare mechanical click, no tone at all. I keep playing anyway, the whole Chopin ballade, and the audience of empty chairs is completely silent. Then I look down and my hands are the wrong age — younger, smoother, the hands I had before the tendon trouble. I finish the piece and there's still no sound, but everyone in the chairs is nodding, so it must have been fine.