This is shame, not least because it's possible they sung 'Hail thee festival day'. This is a hymn of such bizarre musical complexity that it will take me the rest of my life to master, and you only get to sing it this time of year. The tune changes without warning, and as far as I can tell, there are more syllables to sing than notes to sing them to, so you end up gabbling the second half of the sentence to catch up with the choir.
But to return briefly to pigeons. These are not well-loved birds in clergy circles, because they roost on our historic buildings and erode them with their acidic crap. (Like some members of every congregation. Metaphorically.) Here in the Close the pigeon problem is kept under control by pest control people, who come and fly a Harris hawk to scare them off. The recommended solution--made by jaded parish priests--is to baptise the pigeons. That way you'll never see them again.