Here is a small girl singing Joanna Newsom's "Sprout and the Bean." When the girl isn't yelling over the music in sacred baby tongue and actually sings some of the lyrics (like when she jubilantly shouts, "SHOULD WE GO OUTSIDE!? CAN WE PLAY SOMETHING OUTSIDE!!"), her and Newsom sound a lot a like.
Here's some more of Newsom's "baby singing," a lovely performance of "En Gallop" from 2004 (back when she was more wood nymph than Armani model).
(hat tip to Stereogum)