Dido pens tune for Aguilera

British singer Dido has agreed to write a song for diva Christina Aguilera.

Dido, 32, is so impressed with the Dirrty star's unusual voice she jumped at the chance to pen a track for her.

The White Flag singer said: "I get approached a lot to write for various people, but I decided to do one for Christina because she has got a unique voice."