“Marguerite”

Rated R

****

Opens today at Kahala 8

Questions surround the character of “Marguerite,” surname Dumont, a wealthy woman in 1920s France who devotes her life to singing opera, even though her voice is ferociously off-key. Is she delusional or inspired, a fool or a holy innocent? Or all of the above?

As written and directed by Xavier Giannoli, “Marguerite” is a thoughtful examination of an unusual, deeply eccentric woman. Though very much a piece of fiction, it is loosely inspired by a real person, the American Florence Foster Jenkins (who herself is the subject of a forthcoming Meryl Streep film).

As good as Streep inevitably will be, it won’t be easy to outdo the marvelous Catherine Frot, who just won a Cesar, the French Oscar, for playing the character whose name brings to mind the American actress and Marx Brothers foil Margaret Dumont. (The film won four of the 11 Cesars for which it was nominated.)

A veteran French performer who won her first Cesar for Cedric Klapisch’s marvelous 1996 “Un Air de Famille” and has since appeared in films such as “The Dinner Game,” “The Page Turner” and “Haute Cuisine,” Frot gives perhaps the performance of her career here.

Always possessed of impeccable comic timing, the actress adds formidable delicacy and discernment to her portrayal of an individual whose predicament may sound comic but ends up poignant and disturbing.

“Marguerite” begins in 1921 at a charity concert for World War I orphans put on by a private music club heavily subsidized by Dumont, who is a baroness as a result of her marriage to an impecunious member of the aristocracy.

Initially, the film focuses on a trio of young concert attendees, none of whom has heard Marguerite perform before. Hazel Klein (Christa Theret) is a student singer scheduled to appear elsewhere on the program. Sneaking over the wall are two friends, Lucien Beaumont (Sylvain Dieuaide), a demanding critic (imagine), and Kyril Von Priest (Aubert Fenoy), an ambitious Dada poet.

Also introduced are Marguerite’s solicitous major-domo Mandelbos (Denis Mpunga), a man with an ever-deepening interest in photography, and Marguerite’s husband, Georges Dumont (Andre Marcon), someone with an ever-deepening interest in avoiding his wife’s singing engagements.

We soon see why. You don’t need a trained ear to hear that Marguerite, who massacres the high notes in Bellini’s “Norma,” can’t sing a lick. Her voice is so screechingly bad that a combination of a dubbed voice, careful lip-syncing and sound engineering was needed to make it convincing.

Yet despite her marked lack of ability, Marguerite has the interests and even the soul of an artist. She collects costumes and props from famous productions and has a collection of scores that numbers more than 1,400. Music, which she calls “the stuff of dreams,” is all that matters to her.

Given this, and given her generosity, no one ever levels with Marguerite. They laugh behind her back but are unwilling to wake the sleepwalker. Everyone around her has his or her own self-centered agenda, and Marguerite, too, if it comes to that, sings, in Giannoli’s conception, partially to regain the affection of a husband whose interest in her has waned.

While the plot of “Marguerite” has its ups and downs, what is continually interesting is observing the delicate way Frot delineates her character as the singer prepares for her first truly public performance under the tutelage of the once-renowned, now down-at-the-heels singer Atos Pezzini (Michel Fau.)

Mostly blissfully unaware of how inept she is, Marguerite also has a touching tentativeness and an uncertain air, as if some deeply buried part of her suspects the worst.

Her innocence and lack of guile can be seen as a kind of sophistication, and the film that bears her name leaves us wondering whether her naive sincerity counts for more than all the knowing cynicism swirling darkly around her.