Balance issues in a crowded room seems to be a common thread for those of us with ANs, but in varying degrees.
Because I have no vestibular function on either side, I will always have balance issues period. That being said, a room full of moving people is my "worst case scenario." I refuse to become a hermit because of this so there are several things I do when knowing I will be confronting this situation:
1) make certain I have adequate rest beforehand
2) limit my caffeine intake
3) remain as much as possible to the perimeter of the room, unless I have someone's arm
4) find a seat on the outside edge of the room, if possible
5) keep my gaze firmly focused on something that is not moving when I am standing
6) stand slowly and regain my "bearings" before trying to walk
7) do not turn my head quickly
stay in a well-lighted area
Although I am not currently singing in our church choir, the most stressful part of being in the choir was processing, unless I was leading. Following a swaying choir member totally disoriented me. I finally gave it up, but not for that reason, but because I began having vocal issues when my tumor was regrowing and it did not resolve post second surgery.
I will say that fatigue is the biggest culprit in making me disoriented in a crowded room so I am very careful when I am tired. Therefore, I really do try to follow my rule #1.