Hi Fred,
One of the interface 'difficult' areas with GPO is its requirement that every different voice needs to be on a separate midi channel.

That is nothing to do with Composer, but a GPO requirement, and it is understandable as GPO's origins are in orchestral music where there is one instrument per stave (eg violin, cello etc). I have found with GPO a similiar problem with their organ sounds, that to change sounds requires a new midi channel, which means a new stave.

In another thread, I have been suggesting to Mark (and he agrees) that the interface these packages needs to be enhanced to make it easier to overcome these types of issues.

And these issues are in no way confined to GPO - every sound source package that I have used works differently and has another set of equally annoying issues.

Cheers ... Clyde