I’ve always loved this song, and I’m particularly pleased with the way this recording’s come out, so off you go and listen to it.
Perhaps it’s because I did Latin O Level – rephrase that, it’s definitely because I did Latin O Level – but I’ve always had a soft spot for macaronics, songs that dip in and out of other languages (usually Latin). Unto Us A Child Is Born is another seasonal example. In case your Latin’s getting a bit rusty, the chorus here translates as “I bring in the boar’s head, giving thanks to the Lord”; the single lines of Latin at the end of the each verse translate as “as many as are at the feast”, “[let us] serve it with a song” and “in the royal hall”. The last line of all means “it is served with mustard”(!).
For the arrangement, I had a copy of the sheet music with four vocal parts, but in the end I only used it for part of one line; the rest of the harmonies I either got from Jon Boden & friends’ AFSAD rendition or made up myself. Writing them out, and playing them against each other with Noteworthy, was essential; some combinations that look fine on the stave sound dreadful when played.
Fifty-Two Folk Songs 
I did Latin too! And Classical Greek as an extra in my lunch hour! I was the only one left in the end, so had to see it through to the exam. Good job I scraped through the ‘O’ Level!
Macaronics – Not a lot of people know that, and I didn’t (but like them too!) Thankyou, Phil. And for the lilting rendition.