Frank Sidebottom started life as a punk-generation songwriter and musician from Manchester, named Chris Sievey. Under his own name, Sievey had a number of minor successes with his band The Freshies (notably a brisk, Buzzcocks-y number called “I’m In Love With The Girl On The Manchester Virgin Megastore Check-Out Desk”), but in 1984, he devised one of the more bizarre self-reinventions in pop history. He donned a big painted papier-mâché head, and, adopting a high-pitched nasal Northern accent, assumed the role of Frank Sidebottom, an affable, childlike would-be showbiz personality whose knowingly rudimentary songs parodied current pop or hymned his home village of Timperley. In his Sidebottom guise, Sievey had a few droll ideas—not least an EP entitled Frank Sidebottom Salutes The Magic Of Freddie Mercury And Queen And Also Kylie Minogue (You Know, Her Off ‘Neighbours’)—and even achieved some degree of success as an oddball novelty act on British TV. He certainly had a talent as a conceptual or performance artist—one of Sievey’s peculiarities was that he would often keep the Frank head on, and keep up the Frank act, when there was no public to impress, but only members of his band present. And according to journalist-author Jon Ronson, who was at one time his keyboard player, Sievey/Sidebottom had a special talent for calamity, relishing commercial failure rather than success, which he never went out of his way to cultivate.

When Sievey died of cancer in 2010, some admirers hailed him as a genius, but it’s probably fairer to say that he was a sometimes inspired English eccentric and humorist who managed to make one cheap and cheerful gag work reasonably well for a surprisingly long time. But Sidebottom as an undiscovered god of alternative rock? That’s the unlikely conceit imagined in Frank, a new film opening next week, directed by Lenny Abrahamson (What Richard Did, 12; Garage, 07) and co-written by Ronson and Peter Straughan. Frank is not the Chris Sievey story, and doesn’t claim to be, but it is, after a fashion, the story of Ronson’s brief career as keyboard player (before he came to write extended essays in gonzo investigation such as “The Men Who Stare at Goats,” filmed by George Clooney in 2009).</p>

Frank movie Domhnall Gleeson

The Ronson figure in Frank is Jon (Domhnall Gleeson, hugely likeable here), a young aspiring songwriter who spends his days ineptly attempting to cobble together ballads while staring at his computer screen in a dull office job (shades of Quadrophenia, decades on). Then a bunch of madcap bohemians come tumbling out of a van in his seaside town, and it turns out that a band unpronounceably named Soronprfbs, playing in town that night, need a new keyboard player. Jon answers yes to the question “You play C, F, and G?” and lands the gig (by all accounts, Ronson got his job with Sidebottom on the strength of pretty much those qualifications).

Before long, Jon is a fixture in the band, or rather the cult, since Soronprfbs are in the thrall of their mysterious, taciturn leader, Frank (Michael Fassbender), a man who wears a big globe head that almost exactly resembles Sidebottom’s—and never takes it off. That Frank’s Frank is not quite Sievey’s is apparent in the fact that this Frank is no kind of joker, but a very earnest and apparently disturbed Dada master who for a long time doesn’t speak at all—and who, when he’s at last heard singing, bursts into a rather butch agonized basso suggestive of Jim Morrison in one of his self-conscious poète maudit moments.

The extended joke of Frank is the notion, which everyone except us viewers buys into, that Frank is a deep magus whose guidance will lead his collaborators to find their “farthest corners” and make the great album that they have in them. Fame? That’s not so important, except for the more mundane-minded Jon; for his bandmates, the very idea of having an audience at all seems anathema, the worst kind of bourgeois capitulation.

Frank movie Maggie Gyllenhall

The subsequent story follows Soronprfbs from their retreat in the Irish countryside, where Frank puts them through a program of character-building exercises and ramshackle rehearsals; through a trip across the Atlantic to SXSW, where Jon does the unthinkable in trying to muster public interest; and to Frank’s breakdown and beyond. At that point, Jon takes a break to ask himself some serious questions, while the other musicians reach an unexpected apotheosis: without Frank’s mania and Jon’s earnest competence, they actually sound like the Cowboy Junkies, only quieter, which is not a bad thing at all (their big moody super-slow number is actually “On Top of Old Smokey”). Overall, the narrative drifts like a mildly febrile dream—and it may be that an intense period spent in an unsuccessful band is indeed like a hallucination that abruptly ends, leaving you back in your day job, or in rehab, wondering where all the time and all your talent went.

With gentle wit, the film explores two key ideas. One is that it’s never fun to be the straight person in a band—the sensible, studious type who turns up for rehearsals, works hard on the chord changes, and assiduously posts rehearsal footage online to further the band’s career. It’s this behavior that earns Jon the contempt of his colleagues, who are either deranged social outsiders or work very hard at seeming that way (as quite a few rock musicians do, I’m told). Especially thorny is synthesizer player Clara—“Stay away from my fucking theremin!”—played by Maggie Gyllenhaal with a permanently enraged glare and all the sourness of a natural underground aristocrat who never got over being dropped by 4AD after one single.

The film’s other key idea is that we’re all fascinated by, and somewhat cowed by, the figure of the outsider rock genius, the exalted loser who heroically turns obscurity, failure, and possibly ineptitude into something glorious. We’re constantly hearing in the film that Frank is a creative maestro, though there’s little evidence to back this up; the band he’s assembled sounds pretty ropy as they crunch out their mix of stoner prog and indie thrash, and it’s hard to believe, as he intones his trippy divagations (“Screeching frequencies of pulsing infinity!”), that even his most impressionable acolytes are buying into this. The sheer inadequacy of Soronprfbs’ repertoire is one of the film’s running jokes, largely at the expense of Jon, who—despite being saner than anyone else—is more enthused than anyone (“I can’t wait to dive into the creative maelstrom!”). Yet every now and then, the film tries to persuade us that maybe, just maybe… For example, Frank manages to charm an irate German tourist—in fluent German—and before long, she’s thanking him for “this new truth in my soul.”

Frank movie Michael Fassbender

Not only do certain members of the band have histories of mental illness, but Frank’s refusal to remove his painted head is a pathological symptom. Jon, of course, is in awe: “Miserable childhood… Mental illness… Where do I find that sort of inspiration?” But the film pretty thoroughly defuses the myth of madness as a fount of poetic insight, and, along with it, the convention of the melodramatic, all-explaining backstory. “What happened to Frank?” Jon earnestly asks the singer’s father. “Nothing happened to him,” comes the reply. “He’s got a mental illness.”

The sad truth that Frank illuminates is that mental illness in artists can indeed be inspiring—but most often for those onlookers who relish the spectacular chaos of someone else’s life without themselves having to endure the pain. You can read the film’s Frank as mirroring any one of a long line of variously talented musical burnouts, drug casualties, mental patients, or would-be gurus (Syd Barrett, Skip Spence, Roky Erickson, Daniel Johnston, Wild Man Fischer, even that notorious failed folkie Charles Manson), or as having elements of the erratic but genuinely individual outsider figures who managed to sustain long-term careers, like Mark E. Smith, Captain Beefheart, Lee Perry, and Kevin Rowland (whose brief spell in a very unflattering dress may have inspired Frank’s SXSW appearance here). It’s through Jon’s naïvely trusting eyes, and his eventual disillusionment, that we get a chance to measure Frank against such fabled characters, and to find him—and the mad genius myth—wanting or otherwise.

In the end, Frank is revealed to be a middle-aged American with the face of Michael Fassbender (whom, as it happens, Chris Sievey did faintly resemble). And Frank does get a proper moment of glory, one that suggests that maybe Soronprfbs had a decent record in them after all—a thudding neo-psychedelic dirge called “I Love You All.”

Frank is directed with a light touch and few frills (apart from the odd on-screen tweet) by Abrahamson, an Irish filmmaker whose last film What Richard Did was a chillier, tougher dissection of a certain circle of privileged Dublin youth. Despite Irish Film Board funding and Irish stars Fassbender and Gleeson (the latter playing a nerdy English boy), Frank comes across much more like a British film (it was made under the Film 4 banner), with the attendant tendency to be somewhat flip and reassuring and to have some sort of transatlantic “relatability”—hence its American characters and U.S.-set final act. That’s to say that Frank the movie is a little more confused about its own identity than Frank the character. Still, it’s a rare film that gets the phenomenon of rock outsiderdom, and gets it right, but isn’t swayed by the mystique. It’s sweet, just pithy enough, and brings a touch of critical sanity to the question of insanity as performance—it’s a film that, you might say, has its head screwed on right.