Mitsuko Uchida sat at the piano with her back to the audience.

It was an unusual look for a reigning pianist who can fill a concert hall, or sell a new album of 200-year-old sonatas, on the strength of just of her name and face. But over four evenings of performances at the Ojai Music Festival in California, that’s how Uchida played.

It was especially strange, given that she was the festival’s music director, an annual post given to an artist to organize programming and the roster of performers. Throughout the festival’s outdoor campus, her name was on T-shirts and signs, not to mention Vogue-thick program books handed out at each concert.

Then again, we’re talking about Ojai, where open-minded audiences take in music accompanied by nature and snack on freshly picked pixie tangerines. Uchida might have seemed like a headliner, but this festival is about sharing the wealth.

She invited friends and colleagues whom she has known for years, like the endlessly genial Brentano String Quartet. Most heavily featured, during the festival’s run from June 6 through 9, was the Mahler Chamber Orchestra, with whom Uchida often tours in concerto programs that she leads from the piano.

Those tours, though, rarely showcase the shape-shifting resourcefulness the ensemble brought to Ojai. Its members played pop-up miniatures in Libbey Park, the festival’s center, and even at a local bar as a Johnny Cash cover band. Onstage, they took on traditional fare, like heavenly Mozart concertos with Uchida, but also more contemporary works by Missy Mazzoli and John Adams.

At their most touching, they performed “Lichtbogen,” by Kaija Saariaho, who died just over a year ago and was honored with tributes sprinkled throughout the festival. For that piece, her daughter, Aliisa Neige Barrière, led the Mahler players, with authority and grace, while her widower, Jean-Baptiste Barrière, operated live electronics. During the applause afterward, Aliisa held up her mother’s score to the audience.

If the Mozart concerto that followed represented Uchida the performer, the rest of the festival showed her influence as a mentor. She has been a leader of Marlboro Music, a summer program for young artists, for more than two decades, and she handed much of the Ojai real estate to Marlboro alumni, like the cellist Jay Campbell and the violinist Alexi Kenney.

But they weren’t alone among the younger musicians whom Uchida supported. Here are some who appeared throughout the festival’s dozen concerts over 72 hours.

Jay Campbell, cello

Campbell plays cello in the JACK Quartet, an ensemble that, in its adventurousness and communal spirit, would be an ideal group music director at Ojai. (And the quartet has already appeared at the festival.) As a soloist, though, Campbell is an ambassador of musical possibility.

His finest appearances were in 8 a.m. concerts at the idyllic Besant Hill School outside Ojai, and at the Chaparral Auditorium in town. On Saturday, at a performance billed as a morning meditation, he played a version of Catherine Lamb’s “The Additive Arrow,” one of the festival’s high points.

For most of Lamb’s 30-minute piece, Campbell played steady drones of pitches that, at frequencies in multiples of 10, harmonized naturally with one another. Outside, a microphone was placed on the lawn, facing the street and feeding any passing sound to a laptop inside; from there, speakers emitted sound that the microphone had gathered at a specific frequency, but with a range of amplitude that captured the difference in power between, say, a bird and a pickup truck. Often, this would pit control and chaos against each other, but Lamb instead engineers an alluring balance of the two.

The steadiness of Campbell’s bow, and his clarity, required the kind of attentiveness that has long made Minimalism both difficult and rewarding for players; you could see, in his facial expression of meditative focus and flow, how intensely the music had affected him.

Elsewhere, he performed works by Helmut Lachenmann that explore the nature of sound production: “Toccatina,” in which Campbell tapped the strings of his cello with the screw end of his bow, and caressingly bowed the instrument’s scroll and tailpiece; and “Pression,” an A.S.M.R.-like piece of scraping strings and brushing the cello’s wooden body with fingernails. A crow in a nearby tree seemed annoyed, but Campbell’s human audience was visibly rapt, following his every gesture.

Ljubinka Kulisic, accordion

When Campbell played Sofia Gubaidulina’s duet “In Croce,” he was joined by the accordionist Ljubinka Kulisic, who throughout the festival brought virtuosic dazzle and depth to an instrument with a rich history in both folk and classical music.

“In Croce” opens with the accordion high-pitched and light in an analogue of a cello’s arpeggiated harmonic slides. Kulisic repeatedly played the figure, as if in a trance, until Campbell cut into it with slices of downward phrases. Then he was pushed to extremes of passion and power while she unleashed a broad spectrum of color, until, at the end, he took up her theme from the start.

More playful was Kulisic’s account of the John Zorn solo “Road Runner,” a brief piece that unfolds like an anarchic playlist of familiar tunes on shuffle, with a lot of room for improvisation and directions to “make mistakes.” She took it up with a comic spirit, smiling as the audience giggled at the recognition of melodies from the standard repertoire and pop culture, before abruptly switching to something new or slamming her hands down in tone clusters.

At Sunday’s morning meditation concert, she performed, less hectically, works by John Cage: “Dream” and “Souvenir” breathed in long, spare phrases punctuated by dense but harmonious chords. “Cheap Imitation,” a treatment of Satie using chance operations, was conversational and wandering, welcoming at the start and lulling by the end.

Sae Hashimoto, percussion

The morning program that included “In Croce” also featured the sensitive percussionist Sae Hashimoto, in Lachenmann’s “Intérieur I.” A kaleidoscopic tour of sound production, it was so athletic that, when Hashimoto dropped a mallet and picked it up to play the next note without missing a beat, she looked more like a dancer recovering from a flub than an instrumentalist.

At Libbey Park on Sunday, she performed Saariaho’s “Six Japanese Gardens,” gorgeous sound portraits of real places that seemed, in this performance, to also capture Hashimoto’s technique: her shifting timbres amid unwaveringly steady beats; her balance of focus and fluid motion; the magical elegance with which she conjures simultaneous momentum and stasis.

Alexi Kenney, violin

Of the young Ojai artists this year, Kenney had the most mixed success. His reading of Gyorgy Kurtag’s “Kafka Fragments” with the soprano Lucy Fitz Gibbon (another Marlboro veteran) was by turns silly, shocking and mysteriously profound. But his multimedia recital “Shifting Ground,” presented twice at the festival, was a confused attempt at theatrical performance.

In a black-box space at the Ojai Valley School, Kenney played in front of a white curtain used as a screen for projections by the artist Xuan. The program, he wrote in an artist statement, was built around Bach’s Chaconne, the monumental finale to the Partita No. 2 in D minor. He had a similar idea for a brilliant performance at the 92nd Street Y, New York, several years ago; this concert, though, was more digressive, with departures like Angélica Negrón’s “The Violinist,” a piece for violin and electronics, as well as a voice-over of the comedian Ana Fabrega recounting a musical nightmare. It was charming, but it also relegated Kenney to a soundtrack performer.

Kenney is on the right path, though, in thinking critically about the format of a recital. That he’s curious, and willing to experiment, reflects the promise already evident in his playing.

From a seat at the sides of the theater, you could almost ignore the video art and focus on that purely technical side of his artistry, the side that was even more visible in Biber’s Passacaglia on Sunday. Here was the style buried by “Shifting Ground”: Kenney breathes melodies with his bow and body, often relaxing into a gesture, expressive not as an affect but as internalized feeling. Like his Bach, the Biber could be impatient, but only because it was intuitive, less studied than embodied.

The performance recalled one of Uchida’s spare, but deeply communicative recitals. She may be traditional by comparison, but as his mentor she can offer this lesson: Sometimes all an audience needs is good music and a good musician.