Actor Mahershala Ali says he was attracted towards "Green Book" by the challenge of playing an enigmatic character. The film is based on a true story of friendship and relationship between working class Italian-American bouncer who becomes a driver of an African-American classical pianist on a tour of venues through the 1960's American South.

The film is not a biopic but is inspired by the story about friendship between Donald Shirley, an erudite African-American pianist and his white chauffer Tony Lip. "What really intrigued me about Don Shirley was how complicated he was. There's so much to pull from in terms of the things he was dealing with, the things he struggled with, the things that he exhibited a degree of excellence in. The range of things that I was going to be challenged with and tackling... all that was really attractive to me," Ali said in a statement to IANS.