THE ancient radiators are struggling to heat the place and most parents, although flushed with the post-work rush, leave their coats on, tucking and gathering themselves into the wooden pews whose tops have been worn smooth over the years, nodding hello to friends, seeing who's there, trying to make out their child among the cluster of school jumpers or blazers below the pulpit where candlelight picks out the bronze head of the lectern's eagle (whose eye seems to know which of you are there every week, and which of you just this evening).

School carol concerts are fragile, tender occasions, with multiple layers of feeling. Parents are nervous for their performing children; the children are nervous and excited about performing. The music teachers are worried that the Year 6 "orchestra" (one violin, two guitars, seven recorders and a triangle) isn't up to it, and the Head is worried he has let too many non-religious songs through this year (he blames John Lewis, but is prepared to argue that The Power of Love does at least give the right message). All of these feelings swirl up into the stone arches from which an Alpha and Omega symbol ("No, darling. It's not about watches or software or cars." "Well, what is it then?" "Oh look! Mission Impossible's on later!") gently sways.

You cannot see who sings the solo first verse of Once In Royal David's City, but you find yourself scrolling forward in your mind to when this little boy is in the kitchen on Christmas Eve, aged 45, and Carols from Kings begins on the radio and he stops, kitchen knife in hand, almost paralysed with emotion as the young chorister begins the same verse.

Parents raise their mobiles to film it all, little realising that some of the Year 10s are using theirs to send "Happy Textmas" to friends. These days the words mean more to you. "Sing, choirs of angels, Sing in exultation" is truly glorious, while the line "Yet what can I give him/Give my heart" from In the Bleak Mid-Winter pierces like no other. In his short story The Carol Sing, John Updike asks why we "carol these antiquities that if you listened to the words would break your heart. Silence, darkness, Jesus, angels. Better, I suppose, to sing than to listen."

Yet if listening means one simple act of kindness takes place, who is to say the angels aren't among us?