Adaptation beings filling out its cast.

Clint Eastwood has reportedly cast Christopher Walken for his big screen take on the Tony Award-winning musical ‘Jersey Boys.’

Scripted by Marshall Brickman and Rick Elice, ‘Jersey Boys’ chronicles the rise of Frankie Valli and The Four Seasons and the group’s eventual breakup. Eastwood’s film will utilize much of the same music that is heard in the Broadway production, including ‘Big Girls Don’t Cry,’ ‘Walk Like a Man,’ ‘Oh What a Night’ and ‘Sherry.’

According to Deadline, Walken will be playing Angelo “Gyp” DeCarlo, the Jersey mobster who, in the show, served an unofficial consigliore role to the young singers (to be played by Vincent Piazza, John Lloyd Young, Erich Bergen, and Michael Lomenda).

Mike Doyle (‘Green Lantern,’ ‘You’re Not You’) and Johnny Cannizzaro (‘Spin,’ ‘The Muppets’) have also joined the cast, as music producer Bob Crewe, and The Variety Trio founding member Nick DeVito respectively.

Production begins mid-September in Los Angeles with Graham King and Rob Lorenz producing. Valli and Bob Gaudio are on board to serve as executive producers.