Amy Winehouse was never as good as Christina Aguilera !

The Rolling Stone : Jagger: We thought Buddy Guy was a great person to have. We’d played with him before. With the other guests, Jack White had already opened the show for us on many occasions so we knew him. It’s best to have people you know so only Christina Aguilera may have been a gamble, but she’s got a fantastic voice.
Watts: I thought Christina Aguilera was amazing, because often those girls freeze when they dance with Mick. We’ve had some great people - including our dear Amy Winehouse, although I don’t think she was quite well - who were never as good as Christina.