I sat up in the bath when Radio Three played a choral number about shepherds. It was, they announced, by Michael Praetorius. I was astonished to hear that this was the tune to a hymn we sang at my first school in the early 1960s. In the intervening 50 years or so, I had gained no inkling of its identity.

Praetorius was a contemporary of Shakespeare’s, buried in the Marienkirche at Wolfenbüttel (in the centre of modern Germany) in 1621, the year this motet, Quem Pastores, was published. His real name was Schultz, but Praetorius, a Latin translation, sounded better to the learned citizens of the new Protestant polity.

Something about Praetorius’s melody differed from my memory. But I was looking back to a pre-literate time when I had learnt the song from the other children squashed into a room for morning assembly. The room, in a Victorian house on a steep hill, had bare floorboards and a black gloss-painted cast-iron fire surround, decorated with swags of fruit and leaves. I associated the tune with those swags, it having the same swooping shape.