Thanks to LynB and rharv for your very clear response.

The plug-in I am working with is from Swar Systems and it implements a very long list of Indian classical instruments. I have their demo right now, which only has four instruments.

It makes no attempt to map these into a MIDI GM set of any kind. Instead each instrument is an individual preset. This is part of what threw me on how to set things up on this. Using your suggestions, I was able to assign different instances of the plug-in to different ports, and also select and save a preset for each one. I verified that I can exit RB and restart it and see that all this configuration information is NOT in place. Then when I open my sample song it all comes back. This says that all of this configuration data is just for this song and not global to RB. It also says that it must be in the SEQ song file somewhere.

When I saved presets for each instance of the plug-in I went with the default file names that came in the save dialog box. I just wanted to be safe for now, but I assume I can change these to whatever I want. One key issue is that these files all live in the same folder as the plug-in DLL, so I am going to have to be careful to back this up and also think about how to manage this across multiple songs. I should probably create some kind of template song or something for this new "band" and keep it as the starting point.

There are a lot of issues with managing this that I still don't quite understand. It is obvious that the SEQ file has all this configuration in it now. So how portable is this ? What happens if I move this to another machine. The SEQ file is a binary format, so you can't really look to see what's in it easily, but using Notepad2, I looked inside and see lots of strings like this:

C:\Desktop\Music\VST_Plugins\Swar_Demo\SwarPlugData\MN1CLOSD.WAV

Notice - the hard coded paths!!! Yikes - this means that the song is now tied to my hard drive configuration.

Please feel free to send any more comments on this that you can, as I figure out how to do this in a maintainable way.

Also - I am happy to report that the Swar Systems plug-in works just fine and sounds great. I only have the demo right now, which has four instruments. I need to verify that it all works when merging everything down to a WAV file.