Gaudete. I’ve heard a number of versions of this old song in Latin. The King’s Singers give it suitable gravitas. A translation of the first line, which is the most important, is Rejoice, for the Christ is born of the Virgin Mary.
The angel depicted in lights was in central Manchester one year. There were a few in different colours around Albert Square in front of the town hall, where the Christmas market is usually held. I haven’t been into the city centre this year but I know the Christmas market is drastically reduced in scale and the town hall is under refurbishment, so I can’t imagine it’s very festive in the square.