To follow up on that, I wanted to note that the lyric of the show's best-known song, "What Makes Me Love Him?" is almost word-for-word based on Twain's story; I don't think I've ever seen a song lyric so faithfully based on prose, without actually being prose. Here are the relevant excerpts from a much longer passage from Eve's diary, where she tries to analyze why she loves Adam:
If I ask myself why I love him, I find I do not know, and do not really much care to know... I love certain birds because of their song; but I do not love Adam on account of his singing--no, it is not that... It sours the milk, but it doesn`t matter; I can get used to that kind of milk...
It is not on account of his education that I love him--no, it is not that. He is self-educated, and does really know a multitude of things, but they are not so...
Then why is it that I love him? MERELY BECAUSE HE IS MASCULINE, I think.
At bottom he is good, and I love him for that, but I could love him without it. If he should beat me and abuse me, I should go on loving him. I know it. It is a matter of sex, I think.
He is strong and handsome, and I love him for that, and I admire him and am proud of him, but I could love him without those qualities. He he were plain, I should love him; if he were a wreck, I should love him; and I would work for him, and slave over him, and pray for him, and watch by his bedside until I died.
Yes, I think I love him merely because he is MINE and is MASCULINE. There is no other reason, I suppose. And so I think it is as I first said: that this kind of love is not a product of reasonings and statistics. It just COMES--none knows whence--and cannot explain itself. And doesn`t need to.
And here's Harnick's lyric (though he has since revised it to take out the "if he abused me" part):
What makes me love him? It's not his singing;
I've heard his singing; it sours the milk.
And yet it's gotten to the point
Where I prefer that kind of milk.
What makes me love him? It's not his learning;
He's learned so slowly his whole life long,
And though he really knows a multitude of things,
They're mostly wrong.
He is a good man, but I would love him
If he abused me or used me ill.
And though he's handsome, I know inside me,
Were he a plain man, I'd love him still.
What makes me love him? It's quite beyond me;
It must be something I can't define,
Unless it's merely that he's masculine
And that he's mine.
And yet despite all this fidelity to Twain's words, the effect is different. The passage from Twain's story is, like the rest of the story, simultaneously touching and satirical in its portrayal of what it might be like to be the first people in the world, and go through everything for the first time without any pre-conceived notions. "What Makes Me Love Him?" is a good song, but comes off as a fairly conventional song, very similar to "(He's Just My) Bill," which is based on exactly the same idea, a woman who loves a man for reasons she can't figure out. Proving, I suppose, that when you turn something into a song, it makes things different, even if the words are almost the same as they were on the page.