Arthouse director Jim Jarmusch sums up most things with this three-word catchphrase

If Jim Jarmusch can be said to have anything as brazenly branded as a catchphrase, it would have to be “I don’t know”. He doesn’t know – because who does? – how to explain what is going on in America now. “Oh God, please. I don’t mind talking about it, I don’t know what to say about it.” On a smaller scale, he doesn’t know what led him to make a film about the clunky workings of family, just that Father, Mother, Sister, Brother came to him quickly once he had the notion of making Tom Waits and Adam Driver play father and son. “I never really know what I’m doing,” he says. “I’m just trying stuff and working on it.”

Jarmusch has been making films since 1984, when his low-budget road movie Strangers in Paradise captured a new generation of cinema-goers with its conscious cool, defiant simplicity and deadpan humour: the Jarmusch style. That style is still immediately recognisable in Father, Mother, Sister, Brother’s triptych of discrete but thematically linked stories about the relationships between ageing parents and adult children. Quiet in its ambitions – and literally quiet, given how much the generations cannot say to each other – it surprised everyone by winning the Golden Lion at last year’s Venice Film Festival.

Threaded between them is the melancholy sense that nobody really understands anyone else. Adam Driver and Mayam Bialik are siblings visiting their scurrilous old dad, played by Tom Waits, in his rural cabin in the Catskills, where they drink tea and make cautious inquiries about his supposedly precarious finances and current drug habits. In the second chapter, an almost unrecognisably buttoned-up Cate Blanchett and German actor Vicky Krieps, transformed into a wild child with a profusion of pink hair, sit in twanging tension with their frosty mother, played by Charlotte Rampling, in her plush Dublin sitting room.

The elegiac final episode takes place in Paris, where American twins played by Indya Moore and Luka Sabat come to clear out their parents’ apartment. Father and Mother were adventurers. They died when they crashed their own light aircraft. What drove them? Their children – twins, whose own connection is so strong that they anticipate each other’s sentences – have no idea.

This isn’t an anthology, Jarmusch says. “It’s not a film of separate stories. It’s more like a piece of music with separate movements. And the idea of seeing them separately, I would kill myself, because I worked so hard to have these nuances accumulate.” It is a structure he has used before – in Night on Earth (1991) and Coffee and Cigarettes (2003) – that allows him to avoid meeting the demands of a plot. “I love those moments in between. Night on Earth is just taxi rides you would take out of another film. Coffee and Cigarettes is about people taking breaks, not doing the thing they do. Maybe it’s a slacker aesthetic, but it is a poetic structural thing as well for me.”

Poetry was his first field of study. Fifty years on, he retains not only a poetic sensibility, but poetic techniques; where a poet may use verbal echoes, Jarmusch will use visual ones, such as the repeated raising of teacups in each chapter of Father, Mother, Sister, Brother, or the skaters who appear in each city location like migrating flocks of birds. “Repetition and variation are very important to me in everything. In natural phenomena, everything is a variation, in plant forms, animal forms, everything. Variation, to me, is the key to the beautiful mysteries of being alive.”

Bach’s Enigma Variations are one of his many touchstones; he often reaches for musical parallels to what he does. In Father, Mother, Sister, Brother, the silences – no matter how awkward – work as they would in music. “The notes that aren’t played, they make the notes that are played resonate. When you see an action film where every shot is three seconds – cut and cut and cut – I get a f---ing headache. There’s no space in there! So I go in the opposite direction.”

Didn’t he always? His style developed, he admits, out of a contrariness. “When I made Strangers in Paradise, it was at the very height of the beginnings of MTV, with this kind of fast cutting, stylish clothes and being trendy. I thought no, I’m going to do the opposite. So the guys look like they’re going to the dog-racing track; it’s a one-camera set-up with long scenes, and it’s in black and white. So that led to the style which is mine. Which I found, you know.”

Jarmusch is such a perennial hipster; it’s startling to be reminded that he is 73. He pulls up short when asked whether he identifies more with the elderly parents in his film or their mutinous children. “Oh man, I don’t know how to answer that. The Tom Waits and Charlotte Rampling characters have established boundaries around their lives; the children have different lives. I don’t really identify with either, but it’s an interesting thing you bring up.”

He has one daughter, now aged 20. “I am in a way very relieved that I had my daughter later, as an older parent because I would not want to inflict what my father inflicted on me,” he says. “He was very critical, and he was very frustrated. I have love for my father, but we didn’t get along so well. I left when I was 17 and went to have my own life, you know. It’s complicated. There’s no game plan you can follow and it’s different for everyone. And then, later, you realise ‘wow, my parents are quite different from what I thought they were’.”

This is how interviews go with Jim Jarmusch: the reflex I-don’t-know responses to direct questions soon dissolve into mulling and musing over possibilities, a kind of productive uncertainty that permeates both his work and the way he makes it. And while he has plenty to say, he seems instinctively to want to leave that uncertainty about his own work intact. “I wasn’t trying to make a film, really, about family. It’s more observing people without judging them and seeing that yeah, they have flaws, as we all do.”

He writes his scripts alone, working in a woodland cabin not unlike the one he gives Tom Waits in the film. During the shoot, the shape of that script will shift constantly, often at the suggestion of his collaborators. “I’m rewriting while shooting, getting new ideas. Then, in the cutting room, the film tells me what it wants to be. Some people do a storyboard, and they meticulously plot out the film in advance, which is one way to do it. It’s not my way. My gift is more intuitive, not analytical or precise in intention.”

At one time, New York inspired him. Now, he gets more stimulation from the Catskills, where there are still bears and wolves in the woods, and he can spend his time in the recording studio he has built in an old garage. You can’t walk out of the door in New York without spending a hundred dollars, he grumbles. More than it ever was, it’s all about money.

“We are all different,” he says again. “But this idea of leaning into negative energy and narcissism, greed and ego and power is very disconcerting.” He has built his own belief system: he does tai chi, follows a vegan diet, believes in “the philosophy of a single consciousness” and nourishes his own consciousness with microdoses of psilocybin. “Not for recreation, but as a medicine. It helps me try to appreciate being in the present. Which is not an easy thing for any of us, but I’m trying.”

And there’s cinema, of course. He watches a film every day. “We don’t even understand what the universe is, so we’re just lucky that we’re here,” he says, waving at the trees and the beach beyond the garden where we’re sitting. “We’re in Venice! In 10 years this place probably won’t even be here – and we’re here to gather and talk about cinema, this beautiful thing, telling stories with a camera. What a beautiful thing humans do, along with all the f---ed-up things they do!”

It’s a gift, he says, to be a human being. To be part of the single consciousness, at one with the planets. At which point, being Jarmusch, he breaks into a laugh. “But don’t follow me!” he says. “I don’t know what’s going on. It’s all a f---ed-up mystery to me.”

Father, Mother, Sister, Brother opens April 2.

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