Written by Barratier from an original idea by Frank Thomas, Jean-Michel Derenne and Reinhardt Wagner, the film stars Gerard Jugnot, Clovis Cornillac, Kad Merad, Nora Arnezeder, Bernard-Pierre Donadieu and Maxence Perrin.
Set in pre-war Paris, the story follows three unemployed music hall performers who decide to occupy the stage where they were until recently employed. Barratier's previous title, the Oscar-nominated Les Choristes, closed the festival in 2004.
The film, which sold well at Berlin earlier this year, is distributed in Canada by Alliance Films, which plans to release it later this autumn. Sister company Aurum has the title for Spain.
In a statement, WFF president Serge Losique said he was 'very happy to have the festival opened by a film of this artistic excellence and great cast. We are sure that Montreal filmgoers will give the film and its brilliant director the warm welcome they deserve.'