Thank you so much everyone for the ideas. It has given me a lot to consider. Anna's idea was interesting, but not practical for my situation as we typically remove the masks 15 mins before the end to see who it is we have actually been dancing with. I would expect that if I use a messaging system it would only have to fire once a minute, so from what Rolig is saying, shouldn't pose a problem, even though it is going to test my low level of expertise with creating and comparing lists. No matter, a challenge is good.
Thanks again to all 🙂