Clint Eastwood was the ''perfect'' choice to direct 'Jersey Boys'.

Although some eyebrows were raised when the legendary actor-and-director was announced to helm the movie adaptation of the Broadway and West End musical - which charts the rags-to-riches rise of Frankie Valli and the Four Seasons - producer Graham King insists he knew he was the right person for the job from the start.

King explained to Empire magazine: ''I knew he had this musical background and that's what made him perfect for 'Jersey Boys'.

''He'd been struggling to set up 'A Star is Born' and within 48 hours of receiving 'Jersey Boys', he called me and said he loved it. He hadn't even seen the show at that point, so I recommended he go and check it out, so he did and that was when he decided he had to make it. It really was as easy as that.

''He works very quickly; it's been amazing to see his process. He first read the script in March and here we are in December with a finished movie.''

King was also insistent on casting the four stage stars who played Frankie Valli and his cohorts on Broadway rather than hiring Hollywood actors.

He said: ''I've always tried to stay away from gimmick casting. We certainly didn't shut the door on name actors and we looked at a lot of people across the board, but it was hard to envision a movie star playing Frankie Valli. The audience wouldn't buy it and the guys that did the show did such a phenomenal job. It was hard to put anyone else in front of them and think they could do a better job.''