Acapella harmony folk(?) song...help!
 

I think its a female band of singers possibly sisters, the song sounds really old...quite slow like a lament and harmonized beautifully, also it may or may not have the word 'Crow' in the title/lyrics....

I know its all a bit vague but its been driving me mad .. heard it ages ago on 6music I think, and now totally at a loss...

Run Devil Run by Jenny Lewis and the Watson Twins?

Found it
The Unthanks - Magpie
Great song !