The recording had taken place last March in the Abbey Road studios.
Proceeds from the sale of the track will go to the Amy Winehouse Foundation set up by her family, “to support charities and organizations undertaking charitable activities in both the United Kingdom and abroad who help, support, or care for young people,” according to a statement.
A clip is posted on the foundation’s website, showing Amy joking around about her meeting Bennett, one of the giants of American music.
“Can I call him ‘Tone’?” she asks.
The singer was enthusiastic about the duet for Body and Soul, saying: “Our singing together just blended perfectly. It couldn’t have been better.”