Go your own way: "The Ballad of Wallis Island"

You can see exactly where The Ballad of Wallis Island - a passion project for Tim Key and Tom Basden, who co-write and co-star - is coming from. Here is a film that was surely inspired by a) the British folk revival of the past 20 years, a period in which it's often felt as though the country's been dragged back to an earlier era of serfs and weavers, and b) all those news stories about musicians being booked by millionaires to perform varyingly dubious private gigs. The musician in question here is one Herb McGwyre (Basden), one half of McGwyre Mortimer, a boy-girl folk duo who peaked in the mid-2010s before going their separate ways as a result of differences both musical and romantic. Now, however, he's been summoned to the titular isle, not by some gaudy oligarch but MM superfan Charles (Key), a socially maladroit motormouth and two-time lottery winner who has all the money in the world but can't buy any airs or graces. (He is, recognisably, the kind of beardy weirdo Key has come to specialise in.) Charles is so blind to other people's boundaries that he's also invited the duo's other half, the sylph-like Nell Mortimer (Carey Mulligan), in the hope of engineering a reunion of some form; yet she makes land with a new husband (Akemnji Ndiformyen) in tow. And that, really, is the gag: four people on a small island, three of whom don't really want to be there, two of which have an altogether complicated relationship.

There's one further influence here: The One and Only Herb McGwyre Plays Wallis Island, a short Key and Basden wrote twenty years ago, nominated for a BAFTA in 2008. As fleshed out under Steve Coogan's Baby Cow Films shingle, you can see the short in the feature, and the TV experience in the film. James Griffiths, who directed the short, shoots in widescreen that lends the island's exteriors even greater scope, and conjures a specifically British melancholy from a procession of overcast skies. (No-one here had the money to sit around waiting for the sun to come out again: it's not The White Lotus.) Yet his dramatic focus is on small groups of people, caught for the most part huddling in narrow, intimate close-ups. It's been carefully developed, by which I mean this core creative team hasn't thrown out or overwritten that which worked so well the first time around. Key and Basden appear to have spent the eighteen years between short and feature sticking to their guns: they're character actors who've written themselves prime character parts, and resisted turning them over to bigger, better-known and more saleable names. Key's peculiar genius lies in making arguably the most annoying man in the world (or just on this island) seem likable - Charles means well, even when he's speaking abject nonsense, which he often is. If Basden is cast as the film's sadsack straight man, washed up in multiple senses, he mines the depths of feeling in these songs with consummate skill; he gets us to understand why Herb felt he had to pick up a guitar in the first place. Mulligan, meanwhile, is acing the film's trickiest assignment, etching a woman who every man on screen is at least halfway in love with, while finally defending Nell's right to go her own way.

The Ballad of Wallis Island is so shruggy and casual for much of its running time that it's a genuine, pleasant surprise when real dramatic stakes emerge come the second half. Funny little characters though these may appear, they've been built up - scene by scene, gesture by gesture - into people with hopes and dreams, hearts to be repaired or broken, songs still to be sung. (One of the film's virtues: it understands that music means so much to us because it comes from - and speaks to - some place deep within us.) A certain greenness manifests in the film's one glaring story flaw, involving a character who's conveniently packed off out of the way for the central stretch before returning with a whole new personality: this late key change is blatantly introduced to crank up the drama, when Ballad has been shuffling along just fine. That's a pity, because elsewhere Key and Basden's story instincts are nothing if not sound: the closing stretch benefits hugely from its refusal to go down the expected path when it comes to all matters McGwyre Mortimer. It helps, too, that this script is simply very funny; two or three laughs per page as standard, including a glorious reverse-reveal involving tennis balls and a peerlessly engineered pratfall over and through a notionally harmless bowl of crumble. (Again: it could scarcely be more British.) The bonus is that it's very charming with it. From the comedies of Bill Forsyth to the more recent likes of Richard Bracewell's The Gigolos, history has shown that we do these types of projects well in this country. At a time when the American film industry has all but abandoned comedy to the small screen - and America has very little to laugh about besides - we should really make more of these types of projects in this country.

The Ballad of Wallis Island is now showing in selected cinemas.