From AICN...
   
  bib
   
    Mos Def = Chuck Berry
  -->          
Like the headline says.   
  The project is called CADILLAC. 
    the film 1950s Chicago and follows the turbulent but exciting lives of Leonard Chess, who founded Chess Records, and the label's artists, including Waters, Little Walter and Howlin' Wolf. 
  
  ...says THIS ARTICLE in Hollywood Reporter. 
  Adrien Brody will play Chess, Jeffrey Wright will play Muddy Waters, Beyonce Knowles (unrelated to Harry) will play Etta James, and Gabrielle Union will play Muddy Water's girlfriend. 
  I'm still trying to shake memories of Def's nasally challenged character in 16 BLOCKS, in which he was fine but that voice...that voice...
  This is a pretty interesting group of people about a fascinating time; could be a cool project.