Well, up until now I've usually just set up treble and bass clefs and called them percussion (assigning to them GPO's Basic Orchestral Percussion Combo). Snares, bass drums, etc. are supposed to have their own tracks with those little x-shaped notes rather than pitched ones, but frankly I couldn't be bothered to create a proper percussion setup.
...Not anymore! I'm trying to "do things right" now. So, I tried inserting a Bass Drum track in Overture (rather than a bass clef labelled "Bass Drum"). In the Setup Track dialog, where the starting/transposed clefs should be are some symbols and labels. It's stuff like, "C-1," "position", etc., and frankly I can't make sense of it. I am guessing that this is configured for standard MIDI percussion. So how can I get it in tune with GPO's percussion?
Oh yes, and that goes for snare drums, timpani, cymbals, etc. as well. Thanks!