Susan,
21 is certainly not a burlesque. It's a very ancient and venerable piece with precedents all over Europe. It is at least mid 17thc. I don't sing the last 2 lines and while they do look rather odd to us, they are in keeping with the period. It would certainly make an interesting exercise sorting out which of the words have a meaning of some sort. I would refrain from ascribing 'burlesque' based on chorus alone.

The 'while' is not certain in the manuscript. I prefer 'white' which is what I sing.

Jon,
Apologies for thread drifts.