Well Bob, I've saved my BiaB song and opened it in RealBand. It's now coming back to me some of the earlier issues I had in RB.
Firstly it's OK to delete the generated RealTrack in RB, either the data only or the complete track.
What RB will not allow me to do is to change the track type, because it was a BB track.
I tried generating the midi on a new track. This was for the Bass track. I'm told that I can't do this because there is no Bass track in the current style. And of course there isn't and you are not saying this either because you say to use a midi from any style that I want. However the only way I know to do this is to change the style in the song in RB although I'm not sure that this is the way to go. Or is it?

Incidentally I can generate the midi for the drums, but perhaps there is something different about RealDrums as opposed to RealTracks in this area.

Thanks