))) You could duplicate Real Band with two separate apps, a DAW/MIDI sequencer and BiaB.

This is not correct. There are useful features found in RealBand that are not found in BiaB or a DAW.

An example is the MultiRiff feature (introduced in 2012).

Highlight a section of a track, choose multiriff, and you get to see a menu dialog of possible riffs that would work over that section using the chosen RealTracks. All the riffs are different, no duplicates. Audition them within the menu dialog, until you find the one that works best, and then insert them into your composition.

For example, you can listen to a bunch of different pedal steel riffs, until you find the one that works best with your song.
Or add 3 strumming guitar parts, all different, so that it makes a fat sound.

You can see the MultiRiff feature in action in the RealBand 2012 video... http://www.pgmusic.com/bbwin.demos.htm

Have Fun!
Peter Gannon
PG Music Inc.