I’m sorry Jerry, my previous post was for you, not “Alan”…
Melodica-Me, I don’t know if you are already familiar with the Akai EWI instruments: their mouthpieces include a bite sensor:
and they come out internally with 2 tubes:
one goes to the pressure sensor, the other one to the outside. This could be a perfect solution for a “Silent” Melodica: the second tube could be switched between the reed chamber and the outside, while the first one would always put the pressure sensor at work.
(pictures from http://www.ewiusb.com/)
I guess an Arduino board would be enough to build a prototype but, I repeat, I’m afraid there wouldn’t be enough room in a standard melodica to place all the switches and the cabling…