The song in question can be seen on YouTube. Search for 'Anais Mitchell Tam Lin', and it will come right up.

I applaud Anais M for her excellent diction. However, I can't stand to listen to that high, childish, adenoidal tone for very long.

She's definitely singing 'Carter Hall.' Think of the hall as a picturesque ruin robed in ghost stories, and it becomes a good place to encounter a knight bewitched.
=======
Speaking as an audience member and a former promoter, I ask myself why the heck she hasn't combed her hair. To me, her hair is saying, "You? You are of no importance. Why should I look clean for YOU?"