<< In any event, he didn't show how to re-group/re-position the instruments in the Mixer Window which I don't think is possible at this point in the development of BiaB. >>

Hopefully the wish will be seen by the developers and added to the Mixer. But for informational purposes, any BIAB Mixer track can be moved to any other BIAB Mixer track using the Edit\Copy/Move command. There are restrictions and limitations making it far from ideal, but it's possible to re-group/re-position instruments in the Mixer Window.

However, the method Mr. Henry Clarke demonstrated is the most elementary method of adding multiple RealTracks onto a single BIAB Mixer Track. For years, BIAB has had a fairly obscure but versatile tool, an 11 track sub-mixer, for each of the original 7 BIAB Mixer Channels called Legacy Channels, (Bass, Piano, Drums, Guitar, Strings, Melody and Soloist.) This is a very powerful arrangement tool that's only limited by someone's arranging imagination. It has a lot of settings that perform similar to tweakable pre-sets.
Tracks can:
. Play instruments in sequence
. Play all instruments simultaneously
. Alternate instruments by selected number of Bars, Part Markers, Choruses or whole song
. Can duplicate a RealTrack using the Duplicate Button any number of selectable times from 0-10. PG Music recommends using this feature to thicken vocals or instruments. For instance, a four part vocal duplicated 10 times becomes a 40 piece choir.
. To take advantage of the Duplicating, Each sub-mixer track has panning and volume leveling
. Any RealTrack can be used in any sub-mixer slot. As noted above, a RealTrack can be used multiple times on a track
. Each of the original Legacy Tracks RealTrack Medley Maker sub-mixers operate independently from the others

This tool obviously eliminates the seven instrument limit myth so even if a user hasn't upgraded to a version with Utility tracks, it's easy to compose a song containing dozens of instruments in a single arrangement, first generation render in minutes using nothing but BIAB.

To find the RealTrack Medley Maker, it can only be opened on a track that is loaded with a RealTrack. Open the RealTracks Picker, select a track that has a RealTrack, and click the Medley Button for the RealTrack Medley Maker...

BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.