https://www.pgmusic.com/usertracks1.htm

"You can pick and choose which ones you want to record, and this added material will give your style things like:

song endings
additional material for greater diversity in your style
additional common chords like sus, dim
additional jazzy chords like maj7, m7, m7b5, etc.
additional less common chords like 7b9, 13, mmaj7, etc.
You can also create your OWN chord progressions to add to your UserTracks style! Just make your own custom progression in Band-in-a-Box®, record along with that chord progression, and save the .sgu+.wav in the same folder as this file, and Band-in-a-Box® will automatically add that material to the UserTrack when it is used."