Musikman, I would use some kind of GM or XG (soundcard or softsynth) device for the accompaniment and then use the Trinity for the multivoices. You can use the MIDI mapper to assign the accompaniment channels (9-16)to the internal synth and the multivoice channels (1-8) to the external Trinity. That is as far as I would go with redirecting things with the MIDI mapper. I tried to install an IDF file in which I redirected the harmonica patch to strings using IDFedit. But whatever I tried in the multimedia configuration tool, it kept blowing the harmonica.
JM