<HTML><BODY BGCOLOR="#ffffff">Hi Gerald, Bedding the keyframe is in fact the contact between the key frame and the keybed.  Improper bedding can result in tone loss.  Remember Newtons' law?  For every action there is an equal and opposite reaction.  The energy you put into the action you want to be transferred to the hammer.  If the action is improperly bedded, some of the energy is lost.  Instead of key movement transferring into hammer movement, you have some energy being absorbed by the key frame in the form of "bouncyness." This can result in tone loss.  It also doesn't feel that good on your fingers, and you get a lot of "thunks" in the action. I believe most technicians raise the balance rail glides, bed the back rail, then the front rail, and lastly, lower the balance rail glides.  This all sounds nice and simple, but you didn't ask the question of how this is achieved. My interpretation  Mike Bratcher</HTML>