Beyonce Knowles has transformed her dark long locks into a frumpy blonde crop.

But luckily she isn't trying to kick-start any new trends with her ageing 'do' - the Bootylicious star has donned a wig to get in character for her film role in Cadillac Records.

The star portrays blues singing legend Etta James in the movie.

Exploring the 1950s musical era, the film chronicles the life of the influential Chicago-based record-company executive Leonard Chess, and the singers who recorded for Chess Records.

See Beyonce in action below