The fact is you don't really want to "transpose" a portion of a song (I have never known BIAB to do that), what you want to do is "modulate" to a new key. So you have to just write the chords in the new key while BIAB stays in the original key. Then you can use the F5 to change the notation so those reading it will see the change.

The question is, what will BIAB accompaniment do with these new chords written in the new key? Will it play to the chords or play to the key? My understanding is, it will continue to play to the original key. But I dont know! I said I had done this in the past and I actually used two files of BIAB in different keys and combined them in my DAW. I could find no other way.

But I am going to take a break now. I may be getting way out over my ski's or over my head and I don't want to add to the confusion. Fact is I don't know how BIAB is doin what it does most of the time. Lets hear from some other folks on this interesting topic. I will only add that since Scaler2 came out, I don't worry much about this stuff any longer as it is a very good tool to manage key changes and modulations.

I will download your file and get back at some point. But a chord will never be something different in another key unless you establish the new tonic of the new key. So add a /A to help set the tonic then the new relationship to support the key change is established.

Dan

BIAB – 2025, Reaper (current), i7-12700F Processor, 32GB DDR4-3200MHz RAM, Motu Audio Express 6x6 - My SoundCloud (Tip: No need to create a SC account to hear music - just hit ESC ).