Let's say I'm acting as a librarian for several bands, and one of my trumpet-playing colleagues has a 4 year old version of BIAB, which he uses for practice and for the production of leadsheets in Bb, and which has no RealTracks etc.

If I send him an MGU file that I've created, which includes the chords and melody of a song I've written along with the latest MIDI SuperTracks and RealTracks, will his version of BIAB be able to cope with the leadsheet part of it without his having to change anything?

Obviously he'll have to find a suitable style and choose MIDI instruments to replace the RealTracks (if BIAB doesn't offer to do it for him), what I want to be sure about before I create a brilliant library of thousands is that an older version of BIAB won't just keel over like older versions of Microsoft Word do when they are asked to open documents from the current version.

I get the feeling I'll just have to suck it and see...

[That's a British saying, I hope it gets safely and inoffensively across the Atlantic!]