As his previous picture “Les Choristes” demonstrated, writer-director Christophe Barratier is a moviemaker of the old school, unafraid of nostalgia and sentiment. And in “Paris 36” he offers up heaping helpings of both.

The picture is set in a fairy-tale neighborhood of the French capital in the depths of the Great Depression, against the backdrop of the early euphoria associated with the electoral success of the left-leaning Popular Front led by Leon Blum. There the local music hall, the Chansonia, is being closed by smoothly ruthless local boss Galapiat (Bernard-Pierre Donnadieu), and its long-time stage manage Germain Pigoil (Gerard Jugnot) loses not only his job but custody of his darling young son Jojo (Maxence Perrin), who spends his days playing the accordion as a precocious street musician. The boy’s sent by the government to live with his mother (Elisabeth Vitali), a dancer who’s remarried a well-to-do fellow in the provinces.

Pigoil’s roused from his understandable funk, however, by a decision to try to reopen the Chansonia. Partnering up with his chum Jacky Jacquet (Kad Merad), who fancies himself an undiscovered star impressionist, and leftist political agitator Milou (Clovis Cornillac), he takes over the place and eventually persuades Galapiat to go along. The result, unhappily, is a bust until a young lady from the sticks shows up to ask for a job; Douce (Nora Arnezeder) turns out to be an amazing warbler and quickly becomes a real draw. But her swift success leads to a host of other offers. Happily, the intervention of neighborhood recluse “Monsieur Radio” (Pierre Richard), who has a secret to impart, proves decisive.

Barratier is trying to juggle lots of plot elements and styles here. There’s the whole low-rent showbiz tale, of course. But it’s accompanied by the weepy Pigoil-Jojo story, which ends the picture on a decidedly schmaltzy note. And the thread involving Galapiat, who tries to insinuate himself as Douce’s sugar daddy and thereby creates a romantic triangle with her and Milou, who’s understandably besotted with the girl, is conflated with another involving the younger man’s political activism, taking things into melodramatic territory involving thievery and standoffs with revolvers. Then there’s the quasi-revolutionary background, complete with conflicts between workers and employer-hired thugs and a crypto-fascist outfit into which Galapiat lures the naïve Jacky. That’s an awful lot of bases to cover, and Barratier isn’t always able to draw the connections very smoothly. The splashy look of the film, with an elaborate production design fashioned in Prague by Jean Rabasse, lavish period costumes by Carine Sarfati, and lush cinematography by Tom Stern, adds to the everything-but-the-kitchen-sink atmosphere. (The big stage revue that comes at the close, which looks more like a Busby Berkeley routine than anything that could ever appear on the boards, is surely a bit of overkill.) “Paris 36” sometimes feels like an extravagant French dinner with too many courses.

Individually, though, most of the individual dishes are tasty. The rumpled Jugnot makes a sympathetic protagonist, and he carries off the relationship with sweet little Perrin well—the father-son business isn’t without mawkishness, but man and child keep it from descending into sheer bathos. Young Arnezeder is a charming presence, and she sings well too; and while the triangular matter with Cornillac and Donnadieu is strained, the relationship that emerges with the flamboyant Richard toward the close is quite delightful. Non-Francophiles may be less taken with Merad, whose mugging as the talent-challenged Jacky some will find distinctly irksome.

“Paris 36” is like a souffle overstuffed with ingredients. But it looks great on the plate, and enough of it is succulent to make up for the overcooked portions.