Doepfer

At first we want to finish the TKB, normal keybaord and the control
> box (wheels/joystick/buttons) and then turn into the design of the
> additional controller that still needs a lot of discussion.

Here's one more suggestion for the additional controller: it would be 
nice if it could communicate via midi with Scala software. Then you 
could upload tunings or scales. 

I have no idea if this fits into the concept, but Scala is interesting 
anyway, and free. 

More about Scala at http://www.xs4all.nl/~huygensf/scala/

Greetings

Anton