Wasn't having a huge amount of "no banter" and I was hearing music most of the time (it comes and goes), but it was definitely very quiet for very long stretches, especially the Western Approach. Tried the suggestion: cleared all the journal entries so they showed on the upper right hand side one after another as "completed", only traveled with the war table and the "exit map" points, no fast travel or mounts. I continued to make sure the journal entries cleared after I completed quests and made sure the codex was cleared too.
Started in Western Approach - still very quiet, even with a party I've never used together before. Eventually went to the Exalted Plains and the moment I got there (with Solas, Dorian and Cole, a party I hadn't used together before either) I hear a banter. Ran around doing the quests for about 2-3 hours, still have only visited the southern half of the map. In that time I heard maybe 10-12 banters, a few between all three of them, one related to a companion quest I'd just finished, plus some environmental comments. Once I paused directly after one, came back and unpaused and there was a separate one halfway through, so I don't know what it was about. Also ran back to rest at the camp and another one was halfway over when the "resting" blackout came back, but otherwise there was just banter every 5-10 minutes or so, which was kinda great.
I think there's definitely something to the whole journal thing and it seemed to take a little time to get going. I'll have to try it again tonight to see if it's a fluke, but there definitely seems to be some kind of thing related to the audio system and the clearing of old journal entries that's holding back the banter. If some of it is based on the game thinking "you have not yet left Haven, so this shouldn't be firing" and it's holding back other dialogues that way, that could be some of the problem right there. I haven't actually progressed the main story past getting Skyhold, so I'll also have to see if doing that opens more, but based on that one party I think there should have been a ton already, so...anyway, that was my experience with trying it out.