Well I've found the C9 note - it's not in a drum channel, it's in a chord one. I've almost got it tracked down I think. Maybe it's just in this one .STY file and I'll just strip it out. We'll see.
If it's not an obvious thing, don't worry about it.

I do have some details to work out with how slash chords are arranged. Unless it's easy to explain, I think that'll happen a bit later.

As for ReChord, it's only in the "think it through" phase at the moment. But seems like it won't be too tough. I'll probably rip out the code in my MidiConfiger program that echoes midi events so you can tell if an input midi device is responding ok.

I'll make it dump whatever raw midi events it finds into a file and one of you folks can run it and send me that file. (As I don't have an arranger keyboard). Then once I can figure out the midi events to collect, respond to and send, I'll be good to go.