I live in tampa, but spent a few years in Manhattan. Hearing these apparently experienced choir members would have been a wonderful, wonderful thing to have experienced.
The subways are far more friendly (at times) then one might think, and people can smile and laugh and talk to each other quite easily -- it only takes one of them to start smiling and talking. This choir probably got some weird stares, but i guarantee it got a ton -- a vast majority -- of smiles, hellos, and even a few extra voices added in here and there.
gary in tampa