If you switch styles and the new style has one or MIDI instruments the MIDI instruments will not have a track to land on unless you have previously changed one or more audio tracks to a MIDI track.
Jim, I don't understand this or I completely miss the point about how a change of styles works in RealBand.
The way I understand this process is that when I open my MGU file that was generated in BiaB then RB will re-create the tracks as they were in BiaB. Now, when I change to another style that contains the instruments for which I want to generate I assume that:
1. Any empty non-BB track can be used to generate midi from this new style. The patterns included in the style are used to generate the notes for this track. So, as long as the style has an instrument then we can have the midi generated. Some instruments of the style WILL generate midi, but others simply report that the instrument not available in the style, despite my knowing that it does.
2. Selecting the unused track to midi prior to generation makes no difference and nor do I think it should, RB knows that midi is to be generated and so should, and does, change the track accordingly.
I started completely afresh with a new project.
My project began in BiaB with the previous style (all Real Tracks:
_INTENT R 4/4 ev16 75 Intent Americana Ballad Folk Country 85
where I added previous melody and soloist tracks
Having saved the MGU in BiaB I now open it in RealBand.
Now change to midi style Melisa2 - Melisa2 - Ev.16 Folk-Rock which hosts and Acoustic Guitar.
I do nothing about the BB tracks and leave the empty tracks at their default Audio
On the first empty Audio track I generate the Guitar part.
Well, what do you know, it created as expected!
All other tracks created with their respective mid parts also.
So, with exactly the same setup on the new song I have the whole thing working as expected.
The only problem I have now is why there was an issue in the first place because I've really changed nothing and wasted everybody's time.