StoneBear 
And now for something completely different (and yet hauntingly familiar)... The Agincourt Carol (not all carols are $winterholiday; this one is about St. Crispin's) dates to the 15th century BN(*) and thus is definitely Period for the SCA... the _alternate tune_... is decidedly younger.
https://www.youtube.com/watch?v=q-awExt59Fg
(*) Bede's Notation: using this instead of CE so we're clear about _whose_ Common Era we're using; there _are_ several...
Knitronomicon