Were this a better movie, Jeffrey Wright and Beyonce Knowles would be in serious Oscar contention for their portrayals of Muddy Waters and Etta James. As it stands, they do very admirable work in a movie that isn’t quite up to their level. The film is just fine, but when you have two stars acting their butts off as Wright and Knowles do, you want excellence. Wright does his own singing as the iconic blues performer, as does Knowles as James. Knowles also showcases some significant acting chops, especially in a scene where her character has shot heroin. All the good in the movie is taken down a notch with the glossy portrayal of Leonard Chess (Adrien Brody) who bought off his stars with Cadillacs rather than paying them all the royalties they deserved. The movie has some significant flaws, but its portrayal of the music is truly credible, including excellent work by Mos Def as Chuck Berry.