Tried it out...It works.
An external controller can trigger any note in the current program.
So I can hook up my KORG padKontrol and have 16 extra pads without changing program banks.
This is very useful in live situations.
For instance I want my drummer to be able to trigger samples separately from my pads. So I set up a Yamaha DD-55 (midi drumpads for sticks) to trigger the "D" bank of any given program. I load the samples I want him to be able to use in the "D" Bank, and I use the first three A,B, and C banks for the stuff I want to play live.
With my padKontrol hooked up in addition to the DD-55 the "C" Bank is the only one not immediately accessible by pads.
If I got some kind of 2 to 1 midi box or just used midi thru from something else I could have all 4 Banks at my fingertips so to speak. That would give me 64 pads (all the samples in a given Program) available for immediate live performance.
It's gonna be sick once we work out the details.
p.s. This also works for drum triggers or electronic drums if you have a module or the Alesis trigger I/O...meaning you could have your drumset play the sounds on your MPC instead of using the electronic drum brains which don't sample.
I'm sure people have been doing this for years in professional settings...