What Amy Winehouse recording has just her and a ベース guitar?

Hi,
I'm not real familiar with all of Amy Winehouse's discography, but I remember hearing a song によって her that was just her 歌う along with a ベース as the music... no horns/guitars/drums.
It was a really great song, but I never found out the name, and I have been unable to find it since.

Do any of あなた know what song I am thinking of, and do あなた know where I might be able to find it?

Thank you.