I spent some time idling and testing this morning while doing other things. I ONLY did the war table fast travel fix, there was no mount/dismount, resting, or changing audio settings.
8:30 - Fast travel from war table, then travel to VR - MUSIC!
Start idling at a camp in Emerald Graves with a party I've never used before, Cass/Sera/Cole
8:43 - Cole comment on environment
8:54 - Cole comment on environment
And then it finally gets going
9:02 - Cole & Cass banter
9:05 - Sera & Cass banter
9:10 - Sera & Cole banter
9:20 - Sera & Cass banter
9:55 - Sera & Cass banter
9:58 - Cole & Cass banter
10:20 - it's been quiet for a bit and I need to go do other things, so I fast travel once more to VR just to check - music still plays!
Maybe I just got lucky but there appears to be something to this, I've never had that much banter using any of the other tricks. I wonder how long it lasts for? I'll do more tests later with actual combat and seeing if my bard has stopped being silent.