Perhaps Yamaha needs to build a system that uses the technique that
some human pianists use to accomplish rapid repetition: more than one
finger in succession striking the same key.  (I think I remember a
Gershwin piece where the two index fingers of each hand alternately
hammer at a D.)  If every key were to have -two- solenoids, and there
were logic that sent the signal for each repeated note to the solenoids
alternately, then the solenoids would have time for recovery.  The
limiting factor would then be the piano action, which is the situation
that human pianists encounter.

I would not spend the extra money for this feature, but then I'm not
inclined to buy a non-pneumatic piano in the first place.

Peter Neilson, Sanford, North Carolina