Spare a thought for the American tourist come to ogle celebrities at the 71st Cannes film festival. She’s craning her neck to see who’s on the red carpet, eagerly asking what movie is playing tonight. It’s clearly a big affair – the paparazzi have gone wild. But the crowd is too thick and the distance too great, and try as she might she can’t get her bearings.

It falls to a French student to put her in the picture. “Tonight, it is an Egyptian film called Yomeddine,” he explains kindly. “It is about a man who lives in a leper colony. All his life inside a leper colony.”

The tourist scans the kid’s face to make sure he’s not joking. It transpires he’s not, but she’s amused all the same. “Well how about that?” she says with a snort. “My one night in Cannes and it’s leprosy night.”

It may even be that she’s underselling the thing. Believe some sections of the US media and you’d assume that every night is leprosy night; that this event has turned unsound and unclean, a glamour-free irrelevance. As evidence, pundits point to the comparative dearth of big US pictures, a lack of star wattage and the holes in the programme left by the Netflix boycott. So the Cannes film festival opens under lowering clouds, buzzing with tension, all of its pieces torn loose and in play. I’m thinking this might be a blessing in disguise.

Cannes needed a shake-up and by heavens, it’s happened. Last year’s edition felt cumbersome and conservative. This one is chaotic, uncertain and consequently more interesting. It used to be that the main competition was dominated by grandees. This time, the doors to the citadel seem to have been blown wide open. Yes, the lineup has made room for the likes of Spike Lee, Jean-Luc Godard and 2014 Palme d’Or winner Nuri Bilge Ceylan. But it also contains unfamiliar names such as Eva Husson, Yann Gonzalez and Ryusuke Hamaguchi, all of whom have presumably been selected on merit alone. So far at least, the glamour has largely been confined to the jury. The opening ceremony was a star-spangled affair that saw jury members Kristen Stewart, Léa Seydoux and Ava DuVernay enthroned on white armchairs at the head of the stage while a sequin-bedecked Juliette Armanet sang The Windmills of Your Mind. But even these people, it seems, are determined to throw history in the dustbin. Or as jury president Cate Blanchett put it: “We’re trying to remove names and past and just deal with the present.”

Facebook Twitter Pinterest ‘A rollicking, dangerous imp of film’: Sergei Loznitsa’s Donbass. Photograph: Courtesy of the Cannes Film Festival

After all that, it would be nice to report that Cannes chose to open with some bold, insurrectionist masterpiece. Instead, the organisers plumped for Ashgar Farhadi’s Everybody Knows, a schematic potboiler that folds a kidnap plot in with a land dispute and then sits back to observe the ruination that follows. Penélope Cruz and Javier Bardem deliver sterling performances as the ex-lovers in crisis, but the plot clanks and grinds and rather outstays its welcome.

The critics, then, must look elsewhere for more exotic produce. Happily it’s not long till they find it. Cristina Gallego and Ciro Guerra’s Birds of Passage (which opens the directors’ fortnight) spins a fabulous origins tale, chasing the source of the Colombian drugs trade upriver to the homesteads of the indigenous Wayuu people and finding a fascinating new route through familiar narco-thriller terrain. I also liked Sergei Loznitsa’s Donbass, a rollicking, dangerous imp of a film that serves up nightmarish vignettes from the “People’s Republic of Ukraine”, although it is so pitiless and unremitting I’m not sure I could bring myself to sit through it again. And while we’re about it, let’s not discount AB Shawky’s Yomeddine, the Egyptian leprosy film. This manages to be winning and graceful and just the right side of cloying in its depiction of its middle-aged hero (played by non-professional actor Rady Gamal) turned loose from the colony and setting forth in search of home.

Up in the gods of the vast concrete Palais, the critics gather to see The Eyes of Orson Welles, in which Mark Cousins leafs through the director’s sketchbooks to frame him as a primarily visual thinker. In so doing, Cousins sketches a tender, insightful portrait of his own. The Welles who emerges is a headstrong traveller, “mad for contact with the world”, who bounded out of Wisconsin, through Chicago, Ireland, Harlem and Morocco. Cousins revisits these haunts and finds them now bulldozed or derelict or altered beyond recognition. “Paradises don’t last,” he concludes, which may be precisely what made them paradises to begin with.

Early mornings at Cannes are given over to the clean-up crews. They come pootling through town on electric carts to direct high-pressure hoses on the cobblestones and monuments until every street takes on a faint whiff of detergent. Most of the mess is just superficial spillage. But some stains, I suspect, will take longer to remove.

Full credit to the festival for moving to accommodate the #MeToo movement. The organisers have hurriedly established a sexual harassment hotline and laid on various symposiums to promote the importance of women in film. But the persistent issue is that Cannes’s high-blown art sits cheek-by-jowl with the tawdrier elements of the entertainment industry, to the point where the two become indivisible. The town remains – to adapt Graham Greene – a sunny place for shady men. There are oligarchs’ yachts lined up by the Palais, dead-eyed escorts in the lobby of five-star hotels and bacchanalian revels in the villas outside town.

Facebook Twitter Pinterest ‘The perfect accompaniment to a festival in flux’: Leto, by Russian director Kirill Serebrennikov. Photograph: Courtesy of the Cannes Film Festival

Up until last year, Harvey Weinstein presided over this stretch of coast. Now he, too, is being hastily rubbed out of history. And yet Weinstein was not some rogue interloper, the rapacious cane toad dropped into the garden, but merely the biggest and meanest of a particular breed of Cannes monster. Despite much-needed changes, the place remains a magnet for hucksters and hustlers and greedy, overgrown boys who regard every film set as their own personal sweet-shop. In the dazzling glare of the seafront cocktail reception, we look from the art-house producer to the bling-wearing gangster and struggle to work out just which is which.

It’s dark in the cinema but it’s more joyous there, too. Leto, by the dissident Russian film-maker Kirill Serebrennikov, is a languorous, ravishing, dying fall of a film, spotlighting the fortunes of a new wave garage band in early-80s Leningrad. Our hero Mike (Roman Bilyk) has the shades and the songs, but he’s being gradually outpaced by the younger, smarter Viktor (Teo Yoo) and struggles to maintain his rock’n’roll lifestyle on a caretaker’s wage. In the end, something’s got to give.

Serebrennikov largely shoves the plot to the sidelines to wallow, quite gorgeously, in the pungent atmosphere of the Soviet underground scene. His characters are in thrall to Blondie, Lou Reed and Iggy Pop; in thrall to the transcendent possibilities of the music they love. “Wait!” shouts Mike at one point. “I’ve just had an indomitable idea of quite mind-blowing proportions.” This turns out to be an idea for a chord change.

I’m filing Leto as my favourite competition film from Cannes’s opening days. It’s the perfect accompaniment to a festival in flux: young, raw and gauche, still finding its feet and groping towards glory. When the old order is failing, something needs to replace it. So bring on the unwashed and unclean, the lepers and punks. These are the runners and riders that have arrived to save Cannes.

Coming attractions: next week’s Cannes highlights

Facebook Twitter Pinterest BlacKxKlansman by Spike Lee. Photograph: David Lee/Focus Features

BlacKkKlansman (Spike Lee; screening Tuesday)

Spike Lee reckons he should have bagged the Palme d’Or for Do the Right Thing. Still smarting nearly 30 years on, he has another bite at the cherry with his fact-based account of an African American cop who infiltrated the Ku Klux Klan. If he doesn’t win this time, the jury are advised to take cover.

Dogman (Matteo Garrone; Wednesday)

The Italian film-maker Matteo Garrone scored a breakout hit with 2008’s Gomorrah, and advance word suggests Dogman might be equally fine. Billed as an “urban western”, it’s about a hapless dog groomer who takes on a psychotic former boxer who is terrorising the neighbourhood. We’re seeing this as High Noon by way of Best in Show.

The House That Jack Built (Lars von Trier)

Rocking up the Croisette like the prodigal son comes enfant terrible Lars von Trier. It’s seven years since the director was ejected from Cannes for jokingly saying he sympathised with Hitler, but don’t look to him to have reformed his disreputable ways. Von Trier’s latest is a serial killer story described by its creator as “a film that celebrates the idea that life is evil and soulless”.

Facebook Twitter Pinterest Adriano Tardiolo in Happy as Lazzaro by Alice Rohrwacher. Photograph: Cannes Film Festival

Happy As Lazzaro (Alice Rohrwacher; Monday)

Still only 35, Italian film-maker Alice Rohrwacher is set for her second visit to Cannes with this class-divide fable charting the friendship between a small-town peasant and the local aristocrat. Rohrwacher won the Grand Prix (traditionally seen as Cannes’ silver medal) for The Wonders back in 2014. She’ll be hoping to go one better this time.

The Man Who Killed Don Quixote (Terry Gilliam; closing film, Saturday)

Might Cannes yet provide a happy ending for Terry Gilliam? The director first attempted to shoot The Man Who Killed Don Quixote back in 2000. Now it appears he’s finally done it. Only last weekend Gilliam suffered a minor stroke. But he’s now out of hospital and determined to attend. He wouldn’t want to miss this premiere for the world.