I suggest Yann Tiersen, especially Rue de Cascades.
His tunes are magical and subtle (some are a bit too "french", though), and this one is especially wistful, beautiful and mysterious, feelings with what I associate Changeling with.
I think if the tune is either full of longing and beautiful, or disturbing and beautiful, it's the Changeling music. The decorations change, after all - they can be modern America, medieval France, something with a hint of Asia or Arab - but the feelings associated with Fae stay mostly the same.