Merrill Garbus of tUnE-yArDs has such a brilliant voice. She has some other great songs, but this video is just so weird in the best possible way.
If you get a chance, take a look at some of her live videos too. She lays down and then loops vocal and instrument tracks, and it's pretty cool to see one person make such a full sound.
Her album w h o k i l l came out back in April, and if you sign up for her mailing list you can get a free mp3 download of Bizness.
Picture from here.