Welcome to the forum!

This post should be in the BIAB for Windows or BIAB for Mac forum, where it will get more attention. This forum is for giving tips, not requesting help. You should also state which version of BIAB you have, since sometimes it makes a difference.

Let's start with what you know. Are you familiar with the harmony options that BIAB does have? Under the word Audio on the main screen, there are two pull-down menus. You can click on the M button (for harmony on the melody track) or the T button (soloist or Thru track). There are lots of 2, 3 4 and even 4+1 harmonies.

Can you get something that will give you harmony in the keys needed for the horns you write for? No. You would have to transpose the song and print for each instrument. Are you looking to produce single-line parts for each instrument?

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.