I suspect I'm stretching the definition of Advent here. No matter, here's a link for the mathematicians - to Andrew Viner's great Venn That Tune! Forget my CSE maths grade unmentionable; I just love puzzling out his song titles drawn as venn diagrams or graphs. It must be my inner geek coming out!
He's even got a selection of Christmas carols and hits. More here on Facebook. Sheer genius.
All together now..."Dings....Dongs....Things That Occur Merrily...Things That Are On Low"...