I came back from Texas with a piece of music (13th C) which the gang is going to love. It combines a fragment of a popular song with a long, flowing hymn to Mary. This piece seems to be widespread enough that somebody here may have studied it in a class.

You can hear it on YouTube:

Sancta/Dou video

the words to the folksong are "Dou way, Robin, the childe will weepe, dou way Robin." It means "Get off me Robin, the child will weep," which was apparently the medieval way of saying "I have a headache."

Has anybody encountered this word 'dou' before? It's not in my unabridged dictionary and not in the U of Michigan's online dictionary of Middle English. Could it be Celtic? French?

Any thoughts?