Ian, you wrote:
Those are all songs associated with the "Maypole Dance" and the music is used for the dance.
I got hold of the tune "Come Lasses and Lads", and have it playing in the background while reading these lyrics. I can sort of make the tune match with NOW IS THE MONTH OF MAYING, but not at all with JOAN TO THE MAYPOLE (though I see the similarities between the latter and COME LASSES...).
Just one more case where midi do not substitute for the singing voice, I guess.