Warning: This is a long-winded answer, but, since you asked, I wanted to try to give you the full picture.
I am using a synth keyboard (Casio CTK-7200 (operationally the same at Casio WK-7600)) that is not really meant to be a midi controller keyboard. But, it is the keyboard have been using with my various bands. So, I am still going to use those sounds for a long time while I transition use more sounds through GP.
I guess as an initial point, I am not running the audio from my keyboard through my laptop. I wonder if most people do this(?). But, at this point I do not want to. If anything goes wrong with the computer or GP (user error) I want the synth to be connected directly to my amp. (I am letting you know this because this would probably change my options. For example, I would think I could change settings to block incoming audio from my synth).
On my synth all the normal presets/user tones only work in a single global midi channel. (The default is Channel 1, though I could change it globally for all presets/user tones.)
The synth only sends midi controller data when it is using sounds from the drawbar organ bank. So, I am basically coopting the drawbar functions to use my synth as a midi controller. I think it will work fine.
When you select a drawbar sound, it up 8 faders and three buttons available send midi data. Fine for my purposes, I think.
So far, so good. I can use a sound from the drawbar bank to allow me to use my keyboard as a midi controller for GP.
But, I had the problem that if I was controlling GP, I would hear the drawbar sound layered with it. It was too unwieldy to turn local on/off on my synth depending upon whether I want to use internal synth sounds. (Thinking about it now, I potentially have GP do that(?). But, let’s not go down that road right now. Relatedly, now that GP is connected to my synth, I am realizing that I should be able to use GP to automatically change to the correct sound on my synth for each song. (I am now doing that manually).
That is a long term project I will probably work on. (I think I have several hundred songs that I play with different cover bands with different settings).
So, the initial problem was (without turning local on/off for each song), that when I selected a drawbar sound (which allowed me to use the synth’s 9 faders and three buttons to send midi commands) it would always play the drawbar sound, along with the layered sound on GP. But, I managed to work around that issue by programming a drawbar sound that does not create any internal sound on my synth (I forget what I did, maybe setting cutoff to zero). But, that was a big accomplishment, I thought.
But, then the problem was for any other sound I used from my synth, I would hear my internal synth sound layered with the sound generated though GP.
But, I figured another work around. In order to avoid that layering, I was able to take advantage of something called “Registrations”, which is what you have to use if you want to split or layer sounds in my synth.
So, in Registrations there are multiple “parts”, which can be used for splits. The synth only allows for 2 splits: upper keyboard and lower keyboard.
It seems the different parts are “hard wired” to different midi channels. The upper keyboard split uses midi channel 1 (same as all user tones and presets) and the lower keyboard uses midi channel 3.
So, in one of the Registrations I set by my drawbar organ user tone I created (which did not create an internal sound on my synth) as the sound for the lower keyboard. Then I created the split on the top note of my keyboard. So, that my synth keyboard was functioning on midi Channel 3 (except for the extreme top note). In this way I am able to control GP (with all the drawbar controllers) without creating an internal sound.
Then I ran into another issue (that you guys helped with with) where if I hit another sound, it would send out program change and bank change messages. So, with your help, I figured out how to get GP ignore program change and bank messages sent from the synth
So, now I was able to control GP via the drawbar sound I created in a Registration and if I change to another preset/user tone/registration, it no longer sent out unwanted PC and/or bank change messages
This was a big accomplishment for me. This basically allows me to do what I want. If I stopped here I would be fine.
But, now I am getting a bit greedy.
Right now I am slowly introducing GP into my setup. Basically, the first thing I want to use GP for is horn parts. These are a bit weak on the CTK-7200 in my view. NI Session Horns is a decent big step up.
On one particular song (New Sensation by INXS) I am using a horn sound through GP (NI Session Horns). There is also a sort solo parts where I was going to use the synth’s internal sax sound.
But, when I was playing around with my synth using the preset in the drawbar user bank (not in the Registration I created), when I changed to the preset for the sax it layered it with the horns in GP. OF course, this was to be expected because I was not using the Registration I set up (midi channel 3).
But, it sounded good. So, for that song I planned to use the drawbar sound in my drawbar user bank (not in the registration) to control GP and, during the solo, switch to the sax. It would play the internal sax layered with the Session Horns and it sounded good to my ears.
So, I thought I was set. I would switch songs using next song/next rack space (so not need for program change or bank change messages). But, then I learned that the next song/next rackspace command required you to pick a midi channel.
So, that meant if I selected channel 3 (which I would usually use) I could not use it to use next song/rackspace when I played on midi channel 1 (used in the New Sensations song). So, if I was set up for the New Sensations songs, I could not use the Next Song/Next Rackspace command.
So, that is why I asked if I could enable next song/next Rackspace commands on multiple midi channels (in my case midi channel 1 and 3) or set it to omni so it would receive them from any midi channel (I realize there are programming reasons why you guys did this).
That is where I am. I will look at your suggestions. (Sorry so long-winded).