Hollywood Movie about Chess Records

Cadillac Records is a biographical movie about Leonard Chess, founder of Chicago-based Chess Records. Besides Academy Award winner Adrien Brody as Chess, the movie stars Mos Def (as Chuck Berry), Jeffrey Wright (as Muddy Waters) and Beyoncé (as Etta James).
http://movies.apple.com/movies/sony_pictures/cadillacrecords/cadillacrecords-tlr1_h.480.mov
The movie comes to U.S. theatres on December 5th, European dates to follow in 2009. Its soundtrack is supposed to feature four cover-versions by Beyoncé, including Etta James’ At Last.