The communications from Ralph Nielsen (111117 MMD) and others reminded
me of a long battle I have fought to adjust my Steinway Duo-Art grand
to play soft passages convincingly.

But before I start, I would like to comment on his suggestion that the
"Soft" setting should be obtained by raising the hammer rail and the
roll-commanded soft be achieved by shifting the keyframe as it would be
through the use of the una corda pedal.

This procedure concerns me because of possible damage to the pushrods.
If the shift were to take place when a note is being held or played,
might it not bend the rod or break the dowel that contacts the keys?
As the facings on the key-tails see more and more use, they tend to
show dimples where they are hit by the dowels.  Such indentations would
increase the bending force applied to the rod assemblies, putting them
even more under duress.

Duo-Art's original intent is not clear to me.  Did an artist ever use
the una corda while recording, or did the coder put the soft commands
in the rolls, better to imitate what he heard?  My guess is that the
latter is the case, because -- as John Grant (111118 MMD) pointed out --
not that many pianos equipped with a Duo-Art player had frame-shift 
pneumatics.

Another consideration is the firing of #2 accompaniment when the
keyslip control is set to the "Soft" position.  John Grant points out
that some pianos had this feature while others did not.  I venture here
that this might have been a deliberate decision, depending on whether
the instrument was an upright or grand and on specifics of the action.
Having said this, let me return to the problem in my piano (and many
others), where hole #95 operates the hammer rail.  None of the test
rolls I have used allow intensities to be set with the hammer rail in
its soft position.  The zero levels are adjusted only with the rail
down.  How then should the amount of rail lift be determined?  Too
little lift produces a minimal difference between loud and soft.  If
the rail rises too much, notes begin to drop out.  At the moment, my
setting is 13/16", measured at the treble end, which provides nice
contrast; but not all notes are sounded.

"If wishes were horses," I could turn the soft-rail pneumatic
adjustment screw with the piano assembled.  Then I could set the zeros
with the rail down, open hole #95 to bring it up, and set the travel
screw so that no notes would skip.  But in my piano, this screw can
only be accessed by pulling the keyboard; thus this trial-and-error
procedure would indeed be a trial.  The next time around I think I will
try 11/16-in.  But perhaps other readers might have different
suggestions?

Robert Gates