Hi all.
King lurker here.......and I'm kinda thinking out loud so forgive me if some of this is somewhat cloudy.
Let's say I had a pd patch that was simply a controller for different delay parameters. (i.e. in this case, "Bob's Guitar" signal passes through and the patch offers the following knobs to twiddle: delay time, wet/dry level, etc.).
Now let's say I wanted to control these parameters with another, separate guitar that is effectively silent and is just used as a controller (we'll call this controller-guitar "2nd Guitar"......bear with me here). And by "control" I mean each string of "2nd Guitar" gets different parameters of the audible "Bob's Guitar" to control (the effect happens to be 'delay' in this case).
So essentially, you'd have "Bob's Guitar" that gets "fed" (maybe via midi pickup or something?) to another guitar where "2nd Guitar" controls the delay of "Bob's Guitar" in real time via, say, another midi pickup on "2nd Guitar"?? (I have very limited experience with midi so, unfortunately, there's that.)
In a perfect world, any effect could be chosen and tweaked by "2nd Guitar" and any effect could be combined and controlled by "2nd Guitar's" strings......play a string "fast" and the delay gets "faster", etc.