Nick Cave is the most enigmatic of artists, looking and sounding at once like a fiery Old Testament preacher and a serial killer. In his music he tends to inhabit both personas, veering from spiritual hymns such as ‘Into My Arms’ from The Boatman’s Call (1997), to violent narratives like ‘O Malley’s Bar’ from Murder Ballads (1996). 20,000 Days on Earth, the directorial debut from Ian Forsythe and Jane Pollard, is his latest artistic venture, a unique creation which is a blend of rock documentary, biopic, art-house film and Cave-narrated monologue.

The texture of the film is velvety and languorous, the voiceover distilling into the rich frames like smoke on water. It opens with an intimate shot of Cave and wife Susie Bick in bed together. Incidentally the couple met under the tail of a brachiosaurus at the Natural History Museum. The colour palette of their bedroom is monochrome, intensified as Cave eases himself out of bed with a feline grace that becomes his lean, spectral frame. A close-up of Cave’s unblinking eye swims into view as he explains that there is an agreement between husband and wife that nothing in their relationship is sacred. Everything is liable to become magnified, distorted and mythologized into song-writing. As Cave dresses and walks out of the door, he describes his daily routine, "I eat, I watch TV, I write, I torture my wife." This scripted pronouncement characterises the performative angle taken by the filmmakers. The result is a glowing vision of artifice, rigorously controlled self-fictionalisation and darkly ironic humour.

The film has a number of interesting structural devices, which drive the narrative along, smoothly operating to convey documentary style information without resorting to a conventional interview-driven pattern. We move between a psychotherapy session, studio time with the Bad Seeds, and encounters with various characters, lifted from Cave’s artistic ledger. As Cave drives around Brighton in the rain, people appear in the back of his car, including Kylie Minogue (with whom he duetted on the album Murder Ballads in 1996) and Ray Winstone (who appeared in the video for ‘Jubilee Street’ in 2013). This use of brief vignettes in the liminal space of the vehicle evokes the form of Jim Jarmusch’s Night on Earth, in which the plot arises from a series of encounters in the back of a taxi.

The ironic tone of the piece is brilliantly modulated in the scenes with fellow Bad Seed Warren Ellis. Cave turns up at his door, offering two budgies in a cage as a gift. ‘Hi Warren, I’ve brought you some birds.' The two men, formerly members of The Birthday Party, reputed for being ‘the most violent live band in the world’, sit down to a plate of eels and herbal tea. In the past, Cave’s self-professed method of working a live crowd was to ‘single out audience members and try to terrify them.’ Nowadays, he lives completely teetotal, while Warren Ellis owns an AGA and has very nice manners. A far cry from his previous existence, he reveals, which entailed going to church every Sunday before scoring heroin on Portobello Road. "A little bit of bad, a little bit of good…"

The film’s humour plays on the incongruity of Nick Cave taking part in normal, routine activities such as making social calls, drinking tea, driving a car, being a father and husband. This aspect recalls the striking decision to cast Scarlett Johansson as an alien wandering the Scottish highlands in Jonathan Glazer’s Under the Skin. The Hollywood actress could never be anything other than alien in the mean streets of Glasgow; while similarly Cave is a suited spectral visitor wherever he goes, incapable of blending into the background. As such he makes an ideal subject for a film that is obsessed with performance – the creation and deconstruction of character. Cave views the creation of his image as an artistic exercise; he tends to talk about his past ‘self’ as if it were a completely separate entity. This film is no more a documentary than Nicholas Roeg’s Performance or The Man Who Fell to Earth; it reveals more about the process of self-mythologizing than it does any real truth about Cave.

20,000 Days on Earth is a visually stunning piece, laden with richly saturated images and words. While the scattering of vignettes and episodes is entertaining, the film is most compelling in the scenes in which we gain an insight into the artistic working processes of Cave and his collaborators. The ex-frontman of The Birthday Party appears to have gracefully metamorphosed from rebellious, violent young man to a strange but refined statesman of rock. It is worth viewing simply to hear Cave’s knowingly apocalyptic intonations: "At the end of the twenty-first century, I ceased to be a human being…mostly I feel like a cannibal." At the beginning of the film, Cave tells us that his song-writing operates on the theory of counterpoint. He likes to place two disparate elements together and watch the sparks fly - the example given is that of locking a small child and a Mongolian psychopath in a room together. The piece works as a whole because it shares this vision of counterpoint. One is left with the sense that the melancholic figure eking out the lyrics of love, hate and murder at the typewriter is equally capable of laughter.