A fascinating article by Paul Ridden at Gizmag about Don Gilmore’s self-tuning piano system. It uses sensors on each string to determine pitch, and sends an electrical current through the string to warm it precisely enough to cause it to “relax” — basically expand — giving a lower pitch. It seems to me that this would only work when the tuning goes sharp. I think the normal tendency of strings under tension is to stretch and go flat, in which case this system wouldn’t be much use unless it’s assumed that the whole instrument is tuned a bit sharp to begin with. The other aspect is that the further out of tune a string is, the more current it would draw. It’s only heating them a few degrees and the total cost estimate was about $0.17 US/hour, but you have to wonder… is this thing safe?