"I read his (self-titled) autobiography, which is a very good read," Def told reporters in New York Monday.

"YouTube was really helpful," he recalled. "The autobiography was really helpful because a lot of it is written in the manner in which you would imagine Chuck Berry speaking if he were writing an autobiography, which is sort of flowery and it has this kind of gentlemanly type of story-telling quality to it and you find that a lot in his lyrics. That was one thing, watching clips of him that (writer-director) Darnell (Martin) and the producers had provided me with was very helpful and listening to the music, but also listening to the lyrics. I think the lyrical aspect that touched Mr. Berry's work is very unique and very distinctive; it's something that really sets him apart from the generation of performers that he came up in and sets him apart in general."

Asked if he had the chance to talk with Berry while preparing to portray him on-screen, Def quipped: "No. Chuck Berry was busy. He was too busy to talk to Mos Def about playing Chuck Berry ... He had previous engagements, which was cool."