Here’s a story which you probably didn’t know. In 1972, Italian composer Ciro Dammicco wrote this song, which he subsequently recorded with his band, The Daniel Sentacruz Ensemble, in an amended version called Soleado. In 1974 Soleado became a hit across Europe and various notables, including Vera Lynn, performed and released their own versions with a range of titles and lyrics in at least three different languages – but it wasn’t until Johnny Mathis recorded it in 1976 with the title When A Child Is Born that it was elevated into the Christmas hit parade proper. This, the original, starts familiarly, then becomes something completely different (and very Italian).
Obviously having the original of a famous cover version is sort of cheating on the premise, but I make the rules, so that’s OK.