<HTML>Only Roger attempted to answer the mystery noise, so I'll give the answer. To recap. "On a 25 year old KG2, (5'2" Kawai grand, in very good condition, considering it is in a practice room), there was a strange noise on notes d2 - g2. On a medium to hard blow, it sounded like metal buzz. Upon closer inspection, it wasn't a metal buzz, but a high pitched groan. Not only that, but a very small adjustment on each key and a little rubbing in the right place, solved the problem." The noise came from the jack escaping from the knuckle. I don't know why it did that, and why only on those notes, since all the jacks were under the knuckles in the right place. But I solved the problem by moving the jack 1/64" inch forward, and lightly filing the knuckle. Wim </HTML>