A measure of vitality in opera—or any creative form—is the number of interesting artists it carries into the open space of mid-career. The innovations of early work are frequently flukes. The middle years bring longer strides and deepening ambitions. The sixth opera by the forty-six-year-old American composer Missy Mazzoli premièred, last month, at the Metropolitan Opera, with an air of arrival that seemed leavened by relief. Mazzoli, once best known for her indie-electro band, Victoire, has emerged as one of our leading dramatic composers, and the opera, “Lincoln in the Bardo,” written with her longtime librettist, Royce Vavrek, is both her first Met commission and the company’s first première by a woman. An occasion like that deserves a charismatic, openhearted work, and Mazzoli and Vavrek deliver one in the form of a comedy with a melancholy guise. Based on the novel by George Saunders and set a year into the Civil War, the opera follows Abraham Lincoln as he visits his deceased eleven-year-old, Willie, in the cemetery where the boy lies amid restless ghosts. The President has not resigned himself to the death, and neither has his son.

“Bardo” is a Tibetan term, referring to an intermediate state following death, but its assonance with the English “bard”—one who recites, or sings, tales of lives and deeds—can’t have been lost on Saunders. The residents of the graveyard rehash their pasts obsessively, ritualistically, and all the time. In a basic sense, they can’t let go; they linger, fretting about experiences never tasted, errors left unremedied, vindications not received. Their self-absorption is so great that they do not realize they are dead. (They think they’re convalescing.) They refer to their coffins as “sick-boxes” and complain, like captious hostel guests, about the lack of blankets.

Opera is a hybrid form, allowing for storytelling approaches not available to the novel. In the early scenes, Mazzoli and Vavrek weave two supporting characters, Vollman and Bevins, into a single aria of aggrievement. Vollman, a homely middle-aged printer (sung by the baritone Ryan McKinny), was on the verge of consummating his marriage when a falling beam killed him. Now he rests in a purgatorial state of sexual excitement, fitted onstage with a buffa penis that disturbingly resembles a piñata. (The appendage, lofted by a valiant puppeteer, is briefly played for laughs and never seen again.) Bevins, sung by the tenor Jonah Hoskins, is a young gay man who slit his wrists after being jilted by a lover. His song is an overwrought lament of curlicues and tortured intervals dancing around Vollman’s squarer line, for an effect both dreamlike and uncanny. Their two complaints—love without sex and sex without love—mark a barycenter of human loss, the stuff of operatic duets.

Elsewhere in the Bardo we find three Black people who had lived through slavery and were buried in coffinless graves, and a ghoulish pair of boozy sadists, Mr. and Mrs. Baron, imagined somewhere between the Dickensian and the Dahlian as they teeter in a sick, odd-meter duet. But the heart of this production is the dramatic soprano Christine Goerke, who plays a deceased clergyman known as the Reverend. Goerke is a wonderful actress, funny and free, who can project irony while projecting her voice. The bravura aria that Mazzoli gives her at the start of the second act—soaring and droll, and slowly intensifying—is a musical delight. In another gender-swapped role, the celebrated countertenor Anthony Roth Costanzo plays Miss Elise Traynor, a fourteen-year-old trapped in the Bardo. Her lilting, clucking vocal line may not contribute much to Costanzo’s musical reputation, but the part adds mightily to his repertoire of outré costuming, which includes singing Philip Glass’s “Akhnaten” nude. Miss Traynor—a kind of nightmare version of the Queen of the Night—appears swathed in an enormous, mildewing white dress, its hems nibbled by rubber pig heads. She’s a cautionary tale of what awaits children who “tarry” in this world of irresolution, and the dramatic arc of the opera follows Bevins, Vollman, and the Reverend’s scheme to compel the President and his son to move on.

To Lincoln, Willie’s death is weighted with the Civil War. “I have exported this grief / three thousand times,” he laments. When he enters the crypt and embraces his son’s corpse, his shirtfront glows and throbs like a linked Bluetooth device—the way the production, directed with a marvellous contemporary edge by Lileana Blain-Cruz, signals Saunders’s concept of “occupation,” in which ghosts enter living people and their thoughts. The Swedish baritone Peter Mattei, who sings Lincoln, is tall and rightly renowned for his rich, unmuddy voice, here channelled into plausible Midwestern vowels. Yet his aspect onstage, vexed and exercised and diligently in tempo, is nearer in spirit to the Wagnerian mountaintops than to the lonely terrors of a plainsman, and the dazzling performance he delivers ends up seeming less specific than so singular an opera might call for.