Gambassy blues musician Bobby Rush, who performed the harmonica parts for the character of Delta Slim in the Oscar-winning Sinners, is the subject of a new documentary King of the Chitlin’ Circuit, which will air on Mississippi Public Broadcasting in August. The documentary, directed by Al Warren and produced by Taiwo Gaynor, will chart Rush's seven-decade career and personal journey. Rush, a Blues Hall of Famer with three Grammy wins, has performed with artists including Muddy Waters, Howlin�’ Wolf, Little Walter, Jimmy Reed, James Brown, Little Richard and BB King.