After the agonising tension and brutality of their Oscar-winning opus No Country For Old Men, writer-directors Joel and Ethan Coen return to comedic territory with Burn After Reading, a pithy tale of espionage and infidelity. The film is not classic Coen brothers fare, but there are enough flashes of brilliance to keep us smirking for almost the entire 95 minutes.

A large proportion of those laughs are reserved for Brad Pitt, who slicks up his hair and gamely throws himself into the role of a dim-witted gym employee. Whether he is dancing goofily to music on his MP3 player or attempting to conceal his identity by adopting a ridiculous raspy voice, we cannot help but chuckle at his misadventures.

The double-act with Frances McDormand’s cosmetic-surgery-obsessed spinster is a joy to behold, like when they vet her potential suitors on a dating website. “Does he look like he would have a sense of humour?” she ponders. “His optometrist has a sense of humour,” replies Pitt, consigning that particular respondent to the recycle bin.

Former CIA agent Osbourne Cox (John Malkovich) pens his memoirs, but an electronic copy of the manuscript inadvertently ends up in the possession of gym employee Chad Feldheimer (Pitt) and co-worker Linda Litzke (McDormand). She desperately needs cash to enhance her drooping attributes, so Chad and Linda explore the possibility of blackmailing Osbourne in exchange for the safe return of the disk containing his tome. “This could put a big dent in my surgeries,” remarks Linda dreamily.

Unfortunately, the former agent refuses to pay the ransom so Chad and Linda head to the Russian embassy, intent on selling Osbourne’s secrets to the enemy. Meanwhile, Osbourne’s hard-nosed wife Katie (Tilda Swinton) is engaged in an extra-marital affair with serial womaniser Harry Pfarrer (George Clooney), who has also begun dating lonely Linda. Unbeknown to all of them, the CIA is monitoring every move, determined to find out who is leaking top-secret information to the Russians.

Burn After Reading is peppered with colourful, idiosyncratic characters we love and loathe in equal measure. Malkovich relishes his role as a hard-drinking curmudgeon who cannot believe the audacity and incompetence of his two would-be blackmailers. Clooney essays another charming oddball, not a million miles away from Intolerable Cruelty and O Brother, Where Art Thou?, while McDormand brings a touching vulnerability to her opportunist. The scene where a surgeon draws over her body, to show where he intends to cut, suction and tuck, is strangely moving. Even the smallest roles are gifted brilliant one-liners, like J. K. Simmons as the exasperated CIA boss whose field agents are watching Chad and Linda. “Report back to me when, I don’t know, when it makes sense,” he sighs.

It doesn’t entirely, but enjoy anyway.

Nice guys do finish first in The Rocker, an entertaining, if predictable, rags-to-riches fairytale about a group of talented teenagers with dreams of stardom. Strumming to the same beat as School of Rock — albeit with a younger target audience — the new film from director Peter Cattaneo (The Full Monty) hits some of the right notes, but there’s nothing here we haven’t seen or heard before. Indeed, coming so soon after the 2003 Jack Black film, The Rocker is little more than a feel-good cover version, replete with a denouement where the underdogs prove their not-so-heavy mettle.

Screenwriters Maya Forbes and Wally Wolodarsky tease out gentle laughs, from a musician’s strange pre-concert ritual with vomit to an excruciating chat-up line deserving of a slap in the face (“I would love to spend nine months inside of you”).

Rainn Wilson is a poor facsimile of Black as the anarchic force of nature, hoping to inspire his young charges to greatness. He merrily knocks himself unconscious on low hanging beams, but we merely smile. Half-heartedly.

Rising band A.D.D. loses its drummer to suspension on the eve of the high school prom. Singer-songwriter Curtis (Teddy Geiger) and bassist Amelia (Emma Stone) resign themselves to cancelling the gig. However, keyboard player Matt (Josh Gad) has a solution: recruit his slobbish uncle, Robert ’Fish’ Fishman (Wilson), one-time drummer of rock supergods Vesuvius, who was famously kicked out of the band and has been in an emotional tailspin ever since.