[tomhartman]

In Cubase, I tried:

Sending all music tracks to a MUSIC aux. Music Aux sent to stereo out, and to outputs 5-6 (so I could choose those outs as the instrumental mix).

All background Vox routed to a B VOX Aux, which was sent both to the stereo mix, AND to outputs 3-4 (so 3-4 could be chosen during the bounce of the background vocal mix).

All lead vocals to a Lead AUX. Leads sent to Stereo out only.

Problem was (for one) ...the music AUX had to be sent not only to the stereo out, but to the Background vocal outputs, so I could hear music and backgrounds for that bounce. Therefore during normal playback I was hearing the music twice going out the two mix (since the back vox were going out the two mix). I am probably over tired here but still lost a bit.