Twelve years on(!), this remains a fascinating and genuinely useful thread.

Having compared and contrasted several versions of the song, I can make a couple of observations.

Firstly, there's a big difference between the Child versions and the 'Southern' versions collected by the Gardiners, Butterworth et al. The business with the napkin doesn't appear in the Child versions, which have the woman asking the sailor to "take me up in your arms" and pitch her overboard. On the other hand, the drawing of lots and the suggestion of enchantment only appears in Child A, and the whole passage with the ship being becalmed - or possibly stuck on a sandbank - appears only in the Child versions and Baring-Gould's.

Secondly, several different versions - but very few contemporary interpretations - have a verse in which the man offers to help (in a "why would you need women's help when there's a man standing here?" sort of way), and the poor woman replies "you have no idea what you're talking about" or WTTE. On the other hand, although most contemporary renderings follow Frank Purslow in giving the woman a successful labour and a beautiful baby, this detail is only specified in one of the source versions - Baring-Gould's.

Thirdly, there are a lot of differences between Baring-Gould's "Undutiful Daughter"[sic] and all the other 'Southern' versions; some of the differences bring the song closer to the Child versions, others just fill in the details of the story. Purslow, and the contemporary singers who have followed him, lean more heavily on a single - rather flowery and literary - source than I'm comfortable with.

Fourth, the tune. I've always been dissatisfied with the rather upbeat and bouncy tune that a lot of singers use; I stumbled on Debra Cowan's version a while back and have used her tune ever since. It's an appropriately melancholic but spiky tune, with accidentals appearing and disappearing from bar to bar; it's almost, but not quite, in a melodic minor. It's also - I discovered yesterday(!) - almost, but not quite, the tune recorded by Butterworth in 1909, which Sharp described as having Scandinavian characteristics (make of that what you will). I don't know who tweaked it, but - having attempted the Butterworth tune - I think it's just as well they did.

For performance, I've kept Debra Cowan's tune and stripped down the song to verses that only appear in two or more 'Southern' versions excluding Baring-Gould (plus one or two that I just wanted to keep). What emerges is something singable but very bleak - essentially, woman has difficult labour, can't get help because entirely surrounded by hairy-arsed sailors, asks to be put out of her misery with a quick drowning and burial at sea.

OTOH, Baring-Gould's instincts may have been right - all of this may have been a corruption / simplification of the witchy 'Northern' original. I don't think there's any way of knowing.