N-Dubz rapper Fazer and R&B singer Angel are also joined by the 80-piece BBC Symphony Orchestra for a rendition of 'Wish I Belonged'.
The orchestra is conducted by Jules Buckley for the track and the whole collective will go under the guise Urban Classic.
The acts appeared at London's Hanover Square this afternoon to perform 'Wish I Belonged' as part of its launch, which they announced just hours before on Twitter.
The song will be available to buy from Wednesday (November 7) with all net profits going to BBC Children in Need.
The Children in Need telethon will air live from 7pm on November 16 on BBC One.
Girls Aloud's 'Something New' will also serve as the official Children in Need single in 2012 and will be released on November 18.
Watch the music video for Girls Aloud's 'Something New' below: