Ah yes, a belated Merry Christmas to all..! (At least it's not too late to deliver an on time, "Happy New Year", as well.
A little background here. Felix Mendelssohn (*) wrote the music to what I consider to be the most enduring Christmas carol of all time, "Hark the Herald Angels Sing".
Here's "Blackmore's Night" (**) with their interpretation, along with, another perennial Christmas chart topper, "O Come all Ye Faithful"...
(*) A young Mendelssohn wrote what we know as "The Wedding March", at the tender age of 17..!! Hey, the kid really knew his way around an anthem. (**) Yes, it's THAT Richie Blackmore, of "Deep Purple" fame. (Smoke on da wh-ter and so forth).