))) I am a Guitarist and I tune down a whole step to accommodate my voice yet keep the chord voicing I like to play.

You're in good company. I think Paul McCartney did that on Yesterday - played it in G tuned down 2 semitones so heard in F.

Yes, you can do this in BIAB by using the display button and choose to transpose. We have capo settings, and in your case it's a "negative capo" you want, and we call that "tuned down 2 semitones"

If you do that, If you enter a C chord, it will display as C, but play as Bb. This is the same situation as a tenor saxophone or trumpet, and it works well.

Have Fun!
Peter Gannon
PG Music Inc.