Whether or not you buy into the Dylan idolatry may well determine your response to I’m Not There, which makes the all too common mistake of treating its subject as a misunderstood genius. As a musician, Dylan has established himself as an icon, but as a philosopher he leaves something to be desired. He speaks in riddles, and when he tells a reporter early in the film that he’s more of a trapeze artist than a folk singer, it makes you wonder whether he’s hinting at some elusive Truth or just spouting nonsense.

Todd Haynes, who wrote and directed I’m Not There, seems to regard Dylan’s opaque ramblings as profound, though his take on the Artist Formerly Known as Robert Zimmerman is not always flattering. It is an unconventional, fragmented portrait – one reason, perhaps, that Dylan gave it his blessing – that follows no chronological order, and focuses less on the man than on his carefully tailored image. Tellingly, the film never mentions Dylan by name; he is the ghost Haynes is chasing, personified by six different characters who represent various manifestations of the singer’s elusive persona.

There is Jack (Christian Bale), the serious-minded revolutionary who galvanizes the Greenwich Village underground with his songs of protest; Robbie (Heath Ledger), the cynical movie star whose marriage is fatally fractured; and Billy (Richard Gere), the bespectacled outlaw who represents Dylan’s fascination with the Old West and, more specifically, the fabled showdown between Pat Garrett and Billy the Kid.

Robbie, a womanizing loner exhausted by a life on the road, is the most intriguing, and Ledger plays him with the world-weary resignation of a man whose passions have run dry. It is a straightforward performance, less mannered and more engaging than Bale’s so-so impersonation, but the real star of I’m Not There is Cate Blanchett, who plays Dylan as a drug-addicted burnout at the peak of his mid-’60s celebrity.

With her slender frame, gaunt cheekbones and wildly tangled curls, Blanchett bears the most striking resemblance to Dylan during his Don’t Look Back heyday, though Jude, her flaky alter ego, hardly seems like a man at the height of his creative powers. He is juvenile and self-absorbed, shielding himself from reality behind his oversized sunglasses and thick clouds of cigarette smoke. When he greets reporters on the eve of an ill-fated tour, he remains as impenetrable as ever, a portrait of calculated eccentricity. If we don’t get it, well, the joke’s on us.

Haynes glosses over two of the seminal periods in Dylan’s life – his return from a near-fatal motorcycle crash and his late-’70s conversion to Christianity – but perhaps that’s beside the point. I’m Not There is abstract expressionism, paying tribute to its hero in a fashion every bit as enigmatic and chameleon-like as the man himself. Is it a faux-documentary? Is it a biographical drama? At times, it is both. In the end, we are left with an ambitious misfire that obscures as much as it reveals about one of America’s most prominent yet well-hidden artists.