AIX-EN-PROVENCE, France — I mean it as high praise when I say that at this summer’s edition of the Aix-en-Provence Festival, none of the operas come close to Kaija Saariaho’s “Innocence,” which premiered here on July 3.

Ushering new work into the world is perhaps an operatic institution’s most difficult task. This is an art form so stubbornly lodged in the past that it always feels like a miracle when a “création,” as the French call it, succeeds.

And “Innocence,” which explores the aftermath of a deadly school shooting, does more than succeed. With riveting clarity and enigmatic shadows, and through a range of languages in different registers of speaking and singing, it captures both the promise and darkness of cosmopolitanism itself.

It is a victory for Saariaho and her collaborators, and for the Aix Festival and Pierre Audi, its director since 2018. He managed to hold rehearsals with just a piano last summer, when all festival performances were canceled because of the pandemic, and to shift the premiere seamlessly to this year.

“I have a long career in commissioning,” Audi told The Times recently. “And this is one of the five greatest pieces that I’ve ever been involved with.”

It is hard for even the most beloved works in the repertory, some of which are on offer at Aix through July 25, to measure up to that. It felt symbolic that a moment that was devastating in “Innocence” — a character crushing a handful of cake onto another — returned as a silly, passing bit of slapstick the following evening in Mozart’s “Le Nozze di Figaro.”

Lotte de Beer’s “Figaro” production is an intentional, endearing mess — an eclectic, attention-deficit explosion practically vibrating through different aesthetics, as though on a candy high. The overture is staged as traditional, raucous commedia dell’arte; the first act is a raunchy multi-cam sitcom, on a set that gradually (and literally) collapses into a demented carnival amid the confusions of the Act II finale, complete with human-height penises strolling around.

After intermission, though, the curtain rises on almost nothing — a bed inside a cube defined by white neon bars — and the acting is equally restrained and gloomy. Then the fourth and final act enacts a kind of utopian, queer-feminist knitting collective led by a minor character, Marcellina, the cast draped in garments of Day-Glo yarn. Out of the bed, which has come to be the site of male authority and adultery, an enormous, inflatable fairy-tale tree slowly grows.

Thomas Hengelbrock led the Balthasar Neumann Ensemble in a crisp but sensuously phrased reading of the score. Lea Desandre was a bright, alert Cherubino; Jacquelyn Wagner, a Countess cooler than the norm.

In the title role of Barrie Kosky’s staging of Verdi’s “Falstaff,” Christopher Purves was also different than the norm, at least at the start. In the first scene, Purves’s Falstaff is shown not as the usual gorging grotesque in a fat suit, but as a careful master chef, sensitively relishing his creations — and with, at best, a dad bod.

While Falstaff is often likable, Kosky’s implicit promise is that we’ll admire him, too. This never quite happens, as the production settles into a more well-worn groove, abounding in this director’s trademark vaudevillian touches: men pulling off wigs and dancing in skirts, the works. The title character’s seductions are barely more sophisticated than in a thousand “Falstaff” productions; the merry wives of Windsor’s revenge, little crueler.

The conductor, Daniele Rustioni, led the orchestra of the Lyon Opera with a pacing that was genial but less than diamond-precise. The voices, including that of the game, hard-working Purves, were a touch too small for the roles. The test of a “Falstaff” is the effect of the great final ensemble fugue; here the sequence was pleasant rather than cathartic.

There was musical catharsis to spare in Wagner’s “Tristan und Isolde,” with a supreme cast and the London Symphony Orchestra conducted with lithe flexibility by Simon Rattle. But Simon Stone’s staging — an almost comically realistic evocation of contemporary Paris, from a high-rise apartment to a Métro car — is perplexing, as it purports to explain the brunt of the plot as a woman’s fantasies after learning her husband is cheating.

Perhaps intentionally, but still frustratingly, the production’s line between reality and fantasy keeps getting blurrier, until it’s hard to know who’s really betraying whom, who’s getting stabbed and who survives. But if Nina Stemme’s voice has lost a touch of sumptuousness, she’s never been better as Isolde — singing fearlessly, and ardently invested in the production. Stuart Skelton sings rather than barks Tristan, a tenor’s Everest, and Franz-Josef Selig is a commandingly melancholy Marke.

Aix has long been notable for placing smaller pieces, including new ones, amid canonical titans and grand-scale premieres like “Innocence.” In an enormous former ironworks at Luma — the new art complex in Arles, about 50 miles from Aix — “The Arab Apocalypse” was created as part of the festival’s heartening commitment to connecting southern France and the greater Mediterranean world.

But based on Etel Adnan’s direly expressionistic poems about the Lebanese civil war, with music by Samir Odeh-Tamimi and a sketched staging-in-the-round by Audi, “Apocalypse” was dreary — the score alternating between shivering and pummeling, the action busy but bland.

“Combattimento: The Black Swan Theory” was a grab-bag of early Baroque Italian music, with rich helpings of Monteverdi, Cavalli, Luigi Rossi and more. Silvia Costa tried to corral this gorgeous material into a kind of stylized pageant, a loose trajectory of war, mourning, society-building, more war, more building.

Her images were more mystifying than evocative. But the performance, led by Sébastien Daucé, was musically exquisite, with eight superb young singers ideally blending purity and passion, and 13 members of Ensemble Correspondances filling the jewel-box Théâtre du Jeu de Paume with the visceral force of a symphony orchestra.

Audi’s ambitions are to expand Aix, implicitly taking on the Salzburg Festival in Austria, which opens at the end of July, and is classical music’s most storied summer event. (While Salzburg is redoubtable, the mood, clothing and ticket prices in Aix are significantly more relaxed.)

The program of concerts — which, in Aix, has long been an afterthought to opera, but is a Salzburg powerhouse — will grow, as will the scope of the festival’s productions. With “Tosca,” Aix’s first Puccini, in 2019, it declared that it could cover the red-meat Italian hits. In addition to Luma, Audi has his sights on other unconventional spaces in the region.

Commissions are also central to his agenda; “Innocence” is resounding proof. Seeing it a second time, on Saturday, confirmed the initial impression of its intensity and restraint, its emotional pull and intellectual power.

The production — like “Tristan,” directed by Stone — keenly depicts both the shocking reality of the central tragedy and its surreal reverberations, which carry years into the future. I question only one directorial intervention: The shooter, a student at the school, is eventually shown onstage, played by a silent actor, even though he is not in the libretto.

This dilutes the mystery of the piece, in which all the characters revolve around, and run from, a figure who is absent, a kind of god against whom everyone’s innocence (and culpability) is measured. When he appears in the flesh, the opera’s impact wavers.

But only slightly. This is a quibble with a staging that, in general precisely, aligns with an elegant yet savage work. While recalling the starkness of Greek tragedy, “Innocence” is also among the first operatic barometers of our globalized age’s travails.