Thank you for the replies. We hope that it is just an adjustment of the silent rail; the Yamaha dealer Tech is coming Wednesday! It is true that we bought an acoustic piano that has mechanical keys and hammers (sounds). We also would expect the Disklavier solenoids to push the keys more softly during the Quiet Mode: as if the keys are being played by a quiet human late at night...(not push hard as the MIDI was originally recorded for a large noisy room)...smiles