Some of you may remember that I started a MIDI pipe organ project based around the predecessor of the 4x4 Driver many moons ago, but got distracted before I proceeded very far with it. However, joenotjoe, an electronic music artist from the east coast, had a similar idea and ran with it. He's currently building a solenoid orchestra called JASO (Just Another Solenoid Orchestra).
You can clearly see the 16 channel shield in this picture, with a nice breakout board that Joe was able to source for his project. You can get a similar one from Winford Engineering. I'm considering carrying these as an accessory, what do you guys think?
PS -- Joenotjoe also has some pictures up of fifteen solenoids all wired up and moving.