On the same day that her robe were sold for over $34,000 at an auction, a previously unreleased demo of Amy Winehouse’s greatest song, “Back to Black,” was played by Mark Ronson for the first time on his 6 Music Show. It’s stripped of his signature production and it sounds a little rough around the edges, particularly the drums, which don’t have the same oomph as the album version, but Amy’s voice sounds fantastic, if a little weary. She sings it a little bit slower and her vocals are further back in the mix, giving the song a slightly haunting feel to it. Listen here, and expect to see this song on a lot of Facebook pages and Twitter accounts in less than a month…