“Mr. Mannix? I don’t wanna sound screwy, but someone’s calling from the future?” It’s actually the past that’s calling in Hail, Caesar!, the Coen Brothers’ first proper foray into comedy since 2008’s Burn After Reading. Frequent Coen cinematographer Roger Deakins captures the rich gilded colours of Hollywood in the 1950s on unfashionable film stock, as the narrative uses fixer Eddie Mannix (Josh Brolin) as our conduit for exploring the studio lot of the fictional – but very meaningfully named – Capitol Studios. The Coens cede the film to complete musical numbers, with Scarlett Johansson taking an Esther Williams mermaid number and Channing Tatum channelling Gene Kelly in original number ‘No Dames!’, and their pleasure in recreating a mode of filmmaking that has long been abandoned is clear.

Less robust, perhaps, is the narrative they use to thread these scenes together. Things ultimately cohere into an anarchic vision of Hollywood’s relationship with sociopolitical concerns, with the focus on communism making the film an odd contemporary to the recent Trumbo, but aesthetically the scenes sit awkwardly alongside one another, with the editing often too blunt and mismatched. Beyond the bold individual moments, the film trundles along quite sluggishly, its insouciant comedic impulses weighed down by the moral weight Mannix feels at the duplicity and secrecy his job entails and the peculiar depiction of the communists who snatch movie star Baird Whitlock (George Clooney) from the set of the eponymous biblical epic.

The Coens draw these men – Hollywood writers, mostly, as per Trumbo and the Hollywood Ten – as neither hero nor villain, but almost alien, abductors and convertors. The comic war of words that ensues after Baird awakes proceeds in typical Coen fashion, with the men each granted a close-up to showcase their varying emotional temperaments, but the tone nor the acting is quite sharp enough to make these scenes as stimulating as those back at the studio lot. The Coens have often had trouble at collecting searing observations and vibrant images into a coherent narrative, and the world of Hollywood makes the vignette construction even more pronounced. Inconsistent narration from Michael Gambon, of all people, leaves Hail, Caesar! hanging between different tones and even genres. The approach, in general, is rather wild.

Yet when the film shines, it’s practically blinding. ‘No Dames!’, surely a shoo-in to give the Oscars’ Best Song category back some cred after Spectre’s ignominious win, is absolutely delightful, with sprightly, inventive choreography and an astonishing attack from Tatum, who suddenly seems beamed straight from On the Town. Johansson’s DeAnna Moran is a bawdy diva off-camera, Frances McDormand is a one-scene wonder as an eccentric editor, and Tilda Swinton pulls double duty as quick-talking gossip columnist twins competing for Eddie’s insider scoop. Best of all, surprisingly, is relative newbie Alden Ehrenreich as cowboy Hobie Doyle, whose rising star on the plains gets him suddenly thrust into the more refined world of director Laurence Laurentz’s (Ralph Fiennes) debonair society comedies. The winsome earnestness with which Ehrenreich plays Hobie is wondrous, and allows the actor’s charisma to shine even as his character walks stiffly across set in a stifling tux.

Hail, Caesar! seems to be afflicted by as much of a crisis as Eddie Mannix or Whitlock’s Roman soldier-cum-Jesus worshipper. In lampooning Hollywood’s Golden Age, it frequently succeeds in its affectionate, excessive way. In using the sociopolitical scandal of the time, it succeeds less so, bloating the film with the talk of men whose intellect cedes to bumbling inferiority. Together, they make a disjointed film that time, you sense, won’t remember with the fondness of the many classics it references. But in the moment, it has some moments worthy of salute.

Hail, Caesar! is in cinemas from Friday 4 March.