There is a log of these messages. Go to the Help menu, Utilities, Display Log Text File of Yellow/Green Messages

The message was about the Natural Arrangement feature of BIAB, new last year in version 2017. Here's what it says in Help Index, Natural Arrangement (All Songs):

Natural Arrangements (re-interpret complex chords)

If you give a pro musician a complicated chord progression with fancy extensions like C7b9b13 or Gm11, the musician may reinterpret these rather than playing them exactly as written. This can achieve a much better sounding arrangement because the musician has freedom to choose from similar chord extensions. You can get Band-in-a-Box to do the same thing with this option for all tracks in all songs. (Note: To set this feature for all tracks in the current song, use the option in the Song Settings dialog. To set this for specific track(s) in the current song, right-click on the track radio button, go to Track Settings | Set Natural Arrangement, and select an option.)




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.