I hid a bunch of tracks so relevant view. Here those assigned to master are playing. When assigned to group melodic instead, no play.
So actually (1st sent mixer where drums were unhidden accidentally), in either assignment to master or melodic, the tracks show playing, but the difference is that I hear nothing with the melodic group assignment.
And can a bunch of tracks be reassigned at once or do they all have to be done individually? Hassle going back and forth.