One of the interesting topics to come out of today’s online IRC chat was the notion of being able to do “Key Switching” (all those nice KS instruments – both in GPO and GOS) with the help of an additional “foot pedal keyboard”. The basic idea here is to use the octave (or more) on the foot device to free your left hand. (To be accurate, the whole question of “how to key-switch” was spurred by Nicole’s question of “why does key-switching have to be done on the LEFT side of the keyboard,” to loosely paraphrase her original point.) One thing led to another and then the “foot pedal keyboard” notion was tossed out.
To me, this seems like a wonderful solution for those who key-switch. It frees your left hand to do additional playing (one hand is not always enough for a complicated line and/or chords). I have located two models of “foot pedal controllers” which would seem (on the face of it) to do the job. They are the Behringer FCB1010 (here: http://www.behringer.com/FCB1010/index.cfm?lang=ENG ) and the Roland PK5 (here: http://www.americanmusical.com/item--i-ROL-PK5.html ). Street price for the Behringer is about $150 and for the Roland around $380 (before shipping).
A couple of technical questions remain: If you have a current MIDI controller, how would this second MIDI device “chain in” to your setup? I believe that you’d like it to simply act as an extension of your existing keyboard, but I am unsure of how this would be technically accomplished. Plainly, what you don’t want to occur is for the additional device to appear as a separate keyboard, unless you can have two devices communicating on the same MIDI channel (in which case it would seem to be only a duplicate).
The two pedals things are fairly distinct in design where the Behringer one is more “switch-like” and the Roland is more like what you might find on home organ. However, the Behringer has (to me) the additional advantage of having two “volume pedals” (which could presumably be stitched in through their cabling to your existing keyboard as potential Mod Wheel or other continuous controller).
Seeing as how I mentioned the foot pedals before I had to abort the chat session, I'll continue...
I believe the most common way for patching such a system is that the master controller plugs into the pedals, and the MIDI Out of the pedals actually sends the merged data from both. (My Roland Octapad II does this sort of thing.)
Judging from the Behringer PDF manual, it will do this: "MIDI MERGE function allows SOFT THROUGH and merging of controller and input data". Also, the reviews at Harmony Central also indicate that the Roland does it too.
It looks like the Roland has velocity-sensitive pedals and a lot of performance modes, so it would definitely do better if that's your gig. The Behringer countinuous controllers would be very useful for the GPO scenario, though, and the "switch-like" nature isn't too much of a drawback if your only goal is to do keyswitching (though you'll have to do a little configuration programming on it to get it how you'd like). Plus the price is a lot friendlier!
If you can order through a company with a money-back guarantee, then you might as well give either one a whirl for a few weeks, eh?