In “Erwartung,” Arnold Schoenberg’s compact and eerie Expressionist opera from 1909, an unnamed woman finds herself in a dark forest. She’s searching for her lover, who may or may not be dead, and may or may not have been unfaithful to her. The clammy fingers she feels plucking at her may or may not be merely branches.

That’s the plot, such as it is. The point of “Erwartung” is not action but emotion. It’s a musical rendering, one psychological nanosecond at a time, of the inner workings of the woman’s mind.

The superb production of “Erwartung” (the title means “Expectation,” roughly, but the musical world has always agreed to keep the original) that opened a three-performance run at West Edge Opera on Saturday, July 29, captures every detail of that conception with exhilarating immediacy.

The staging by director Giselle Ty is at once boldly revisionist and faithful to the piece’s spirit. On opening night at the Oakland Scottish Rite Center, New York-born soprano Mary Evelyn Hangley, a former Adler fellow at San Francisco Opera, gave a bravura performance under the eloquent leadership of Music Director Jonathan Khuner.

“Erwartung” was the nightcap in a deftly constructed double bill that also featured Igor Stravinsky’s nearly contemporaneous one-act opera “The Nightingale.” Both works cast an imaginative spell, in different but sometimes complementary ways. Yet it was the 30-minute “Erwartung” that made the bigger and more lasting impact.

The essence of Ty’s conception is apparent from the opening moments, when we see the woman enter a hospital room rather than the literal forest Schoenberg wanted. My skepticism was aroused instantly — if the entire opera is presented as the delusions of a hallucinatory patient in a psych ward, I thought, the drama will inevitably feel safely removed from any sense of actual stakes.

But that was reckoning without the specifics of Ty’s staging or the incendiary brilliance of Hangley’s performance. The woman is not alone in the hospital room; there are doctors, nurses, visitors and a patient in the next bed, all of whom interact with the woman in revealing ways.

On a literal level, this staging sheds new light on some junctures in the libretto. When the woman rears back in alarm at the imagined touch of another person, the moment plays differently if there is in fact another person present. Her supposed glimpse of her lover leads her to embrace and kiss a hospital visitor — a different, and differently wrenching, sort of mistake.

But Ty takes the premise even further. The surrounding characters are played by dancers (local artists Roseann Baker, Arvejon Jones, Felipe Leon, Elana Martins, Marcos Vedovetto and Juliann Witt, all excellent), and as the woman’s delusions grow deeper and take over the stage reality, they begin pirouetting and contorting in eloquent variations.

Still, none of it would have been quite so arresting without the musical power on display. Schoenberg’s score is famously daunting, a stream-of-consciousness sequence of momentary impressions without a tonal center or recognizable formal signposts.

Making this music accessible is one of Khuner’s superpowers (the company’s 2015 production of Alban Berg’s “Lulu” showed that on a large scale), and he shaped the performance with a sure and eloquent hand. Hangley’s singing, moreover — bright, luxuriant and fearlessly on point — was a marvel.

“The Nightingale,” based on a Hans Christian Andersen story, is a less potent creation, but the company could at least boast a magnificent artist at its center.

In her first local appearance, Chinese-born soprano Helen Zhibing Huang revealed a blazing, silvery instrument capable of rendering the songs of the title character in sharply etched glory. A good thing, too — when the entire premise of an opera relies on how beautifully the nightingale sings, the artist in question had better come through.

The score is one of the last products of Stravinsky’s apprenticeship, and it shows his leading musical influences — the orchestral colors and harmonic palette of his teacher, Rimsky-Korsakov, along with the Impressionist moods of Debussy — on the verge of being completely assimilated.

But for all its musical riches, the piece is dramatically inert, and Ty’s production, in which gloom was made to stand in for a fairytale nocturnal landscape, didn’t help it much. 

Aside from Huang’s birdsong, the high points were an all-too-brief appearance by mezzo-soprano Alice Chung as Death, and the arrival of a trio of foreign emissaries in “Barbenheimer” drag (pink business suits and black fedoras).

Reach Joshua Kosman: jkosman@sfchronicle.com; Twitter: @JoshuaKosman