RB and Biab are two entirely different programs. It was amazing to a lot of us a few years ago when they came out with RB and we found out they gave Power Tracks some Biab functions. Awesome. Still, RB is primarily an audio/midi recorder/sequencer it's not just another version of Biab so while it will read and open Biab files, it won't save in that format. Mac's suggestion of using Biab chord detection is ok but the problem is it's never perfect. If you don't have any chords to start with then the chord detection is very useful to create a chart from a midi file because it will give you the basic layout even if some of the chords are wrong and that alone can be a time saver. Since you have the basic tune in Biab already I think it would be faster to use cut and paste on Biab's chord grid to adjust it to match what you did in RB rather than going through the whole song correcting the mistakes that were created by using the midi file chord detection but try it both ways and see. Plus opening in Biab a midi file that was created in RB from an original Biab file loses all the instrument settings, bar settings, maybe harmony, soloist, pushes/holds and of course no Real Tracks/Drums, all kinds of stuff you may have in your original Biab file.

Bob

Biab/RB latest build, Win 11 Pro, Ryzen 5 5600 G, 512 Gig SSD, 16 Gigs Ram, Steinberg UR22 MkII, Roland Sonic Cell, Kurzweil PC3, Hammond SK1, Korg PA3XPro, Garritan JABB, Hypercanvas, Sampletank 3, more.