This is a function I don't use myself so I may be off in a detail or two here. The reason I don't do this is this is much better done in a DAW like Real Band.

First, using bass as an example, we're only talking about MIDI bass parts, not a Real Track bass. You open the sequencer using the big green SEQ button and view the bass track. There you can edit the track either by manually changing the notes yourself or cutting and pasting a midi bass part from somewhere else like a midi file.

After you've done that work you MUST remember to freeze the track using the snowflake icon. If you don't and press Play the Biab style will overwrite what you just did and create a new part.

Having said this, I would suggest you move on over to the RB forum and start learning that program. It works hand in glove with Biab, it has a lot of Biab functions built in and it opens Biab files. But it gives you 48 tracks to work with, the tracks are laid out in a linear fashion like any other DAW and doing cutting, pasting and editing midi is much easier there than it is in Biab itself.

Also no need for freezing tracks because as a sequencer each track stands on it's own anyway, nothing regenerates except for certain specific Biab tracks but you can tell RB to convert those tracks to regular tracks. I won't go too far with that function here, stuff like that is on the RB forum.

Bob

Biab/RB latest build, Win 11 Pro, Ryzen 5 5600 G, 512 Gig SSD, 16 Gigs Ram, Steinberg UR22 MkII, Roland Sonic Cell, Kurzweil PC3, Hammond SK1, Korg PA3XPro, Garritan JABB, Hypercanvas, Sampletank 3, more.