A question of attribution: "Power Ballad"

The latest of director John Carney's Films About Music - striking up the band where 2006's Once, 2013's Begin Again and 2016's Sing Street left off - Power Ballad hinges on the ever-thorny matter of attribution. After one reception gig, Rick (Paul Rudd), the American lead singer of Dublin's most regrettably named wedding band The Bride and Groove, crosses paths with Danny Wilson (Nick Jonas), a former boybander recording tracks for an eagerly awaited solo project. The pair jam, drink, get stoned, jam some more - Carney has always been good on how songs get written - and eventually work up the basis of what becomes "How To Write A Song Without You", a soaring love song that is to this movie what the once-ubiquitous "Falling Slowly" was to Once. (Translation: you better like it, because you'll be hearing a lot of it, possibly even outside of the multiplex.) Coming under sudden pressure from his label, who want a big hit single with which to launch the album, Danny runs - and arguably runs off - with the riffs Rick gave him, something the latter party only becomes aware of after "How To Write A Song" tops the Billboard chart and becomes a global smash. Conspicuously absent from the song's Spotify listing: any co-writer credit. At the heart of the film, then, are questions that seem altogether more urgent in the era of AI-assisted chart breakers: what if a song you helped to write made no money for you and a lot of money for somebody else? Furthermore, what if that song began following you around like the ghost of your own musical career?

It's quite the hook, but then Carney has thus far succeeded in turning riffs on song into a noteworthy directorial career: Once's Oscar-winning pavement poetry was followed by the starrier record-business chicanery of Begin Again, the teenage kicks of Sing Street and the lo-fi DIY charms of the post-lockdown Flora and Son. Hitting the road once more - with a film that hops between Dublin, where Rick resides with his wife and teenage daughter, and L.A., where Danny is based - Carney here reteams with Gary Clark, the singer-songwriter who's provided the (very credible) songs for this director's last few films, and who Eighties pop kids may remember as the behatted frontman of the band called Danny Wilson. (Appropriately, for a film centred on due credit, Carney cues up that group's biggest hit "Mary's Prayer" in one bar scene.) The story being told here has enough granular specificity to make one wonder if it was inspired by something Clark imparted to Carney, whether something that happened to him directly or to a musician he knows - though the script credit, as it turns out, goes to co-stars Rudd and Peter McDonald. Possibly Power Ballad was inspired by a broader truth: that there are now a lot of songs streaming around us, and a lot of songs streaming around us that sound naggingly like other songs, an obvious source of tension and aggravation if you feel your big musical idea has provided the crucial leg-up for a million-selling megahit. (Ask Ed Sheeran and the Marvin Gaye estate.) What particularly hurts here is that Rick feels he had to give up his rockstar dreams in order to settle down: everybody finally knows a song that he's written - but not that he's written it, so it also becomes a matter of bruised ego and wounded pride.

What's crucial is that, between them, Carney, Rudd and McDonald succeed in breaking this idea down into amusing scenes and characters: Power Ballad is that too-rare thing, a genuinely funny live-action comedy. Carney gets a lot from his equivalent of session singers, ushered up to the microphone from the supporting cast: McDonald is good value as Rick's rough-edged bachelor bandmate, and Beth Fallon is a lot of fun as Rick's droll daughter Aja (lol), who insists modern women don't want love songs so much as they want revenge. The direction, however, is at its surest around the two leads. It would be very easy to imagine some version of Power Ballad where Rick turns curdled and resentful - he already appears more than faintly obsessive in pursuing Danny back to L.A. - but no, he remains recognisably Rudd-like: sweet, funny, boyish. Jonas's Danny, too, could have easily been reframed as a strutting Timberlake, but this performance knows this character has got something wrong; Jonas plays the entire second half as a kid who's got his hand caught in the showbusiness cookie jar. We're left, then, with two men who, rather than sit down and talk something out between them, elect to take the circuitous route - and who eventually find themselves nitpicking this song's meaning, rather than addressing the more pressing slight and hurt. This is quite a funny idea in itself: antagonists who, even when riled up, still quite like one another, and may even indeed admire one another. Only the final reels betray the one limitation here: it's all a bit middle of the road, an ode to accepting your lot in life. (Call it the Danny Wilson effect.) But Carney gives us a stirring rendition of that particular song, nevertheless - and the kind of peppy, buoying crowdpleaser that, in the context of the modern multiplex, presents as something of a lost artform.

Power Ballad opens in cinemas nationwide Friday.