"10 of them to the same tune"

For me that is not 10 songs, it's 10 sets of words.

I remain of the view that what makes a song a song, rather than a mere poem, is melody, dynamic, and rhythm.

That's not to say that accompaniment cannot be a menace - the piano for example is usually dreadful with folk song, but every so often someone is so restrained that it works well - I'd have to go to get the sleeves to bear it out but I think I have some of June Tabor's stuff in mind as wonderful (unlike some of her americana, which I cannot abide).

While the original forms should not be lost, to say that only they are valid is indeed to stultify the music.