<html> <body> Hey guys & gals, Please delete some of the stuff you're replying to if it isn't pertinent! This message was 57 MG's where most are 3-7! Thanks. Avery At 03:33 PM 12/20/03, you wrote: <blockquote type=cite class=cite cite>Hi, Don, thanks for your answer. That clear those concepts enough.   But still I suppose that the whole energy transmission of the piano action is responding to this momentum concept very well , mostly I believe because a lot of compression occur within the mechanism (and even on the key bed) and that as  this seem to work like a system that stores energy and give it back when stopped (hence the importance of the hardness of the felts under the front of the key), the direction of these moments are changing the way the hammer is throw.   I can’t imagine the piano action during its move like if it was rigid, only on the paper it looks like it, when playing from soft to forte the kinetic energy delivered is certainly not changing linearly, and the momentum of the whole action stack is certainly playing a role in for instance staccato playing. (it is just an opportunity  to reintroduce momentum !)   To make a string vibrate, is not a deformation necessary then an impact occur, I guess that with voicing we look for a match between the rebound of the string and the rebound of the hammer that allow for the best efficiency in bringing the string in its original vibrating mode in the most efficient way .   Coming back at that less stiff support on the hammer pin side does it help the hammer to keep more energy vs. the one that is lost in the pinning at hammer/string contact (decoupling) ?   Sorry for my poor terminology, as often the things us technicians have a feel for because we have meet them in the field, are not easily understood by ourselves with the use of physics (particularly when like me I did not study those theories enough !)   BTW simples reminder like the fact that drilling a lot of holes in a key can’t help in stiffening it are of great value indeed. thanks Mr Ellis ;>)   Happy Christmas , and best regards   Isaac OLEG  </blockquote></body> </html>