It is difficult to believe that Jane Birkin is subject to the ultraviolet revelations of the modern world, stifled by the monotony of quarantine, and using videoconferencing technology for interviews. But here she is, beaming in from her Parisian flat on a weekday night in mid-February. She’s wearing wire-rim oval eyeglasses, shoulder-length auburn hair and at 74 still conveys the indelible radiance you’d expect. At any age, Jane Birkin will always be Jane Birkin.

“The first part of quarantine was miserable to be so cut-off and lonely,” she says, recounting the past year. Her London accent remains mellifluous, a crisp elocution stemming from being part of a three-generation lineage of actors (which is now four if you include her daughter, Charlotte Gainsbourg). “My bulldog died, and you realize how much company matters. But this last bit, I’ve been lucky because you can do interviews and be on television and go into radio stations. So if anything, I’ve had lots of human contact, which is all I love.”

She has just released her latest work, the elegiac “Oh! Pardon Tu Dormais,” her first album of original songs in more than a decade. Inspired by a play that Birkin wrote in the early 1990s, the orchestral compositions assumed a natural gravity toward the anxieties of love and death, the lingering specters of her former paramour, Serge Gainsbourg, and the tragic loss of her daughter, the photographer Kate Barry, who fell from her fourth-story Paris apartment in 2013. (Suicide was suspected but never confirmed.) These are exquisite seances in line with the sonic traditions she pioneered a ­half-century ago, but suffused with the darkly tinted wisdom of a life entering its winter.

The advancing years aren’t particularly charitable to anyone. Birkin survived the loss of Gainsbourg, who continued writing songs for her until his fatal heart attack in 1991. Four days later, her own father died. The passing of Barry — Birkin’s daughter from her first marriage to the British composer John Barry (best known for composing the James Bond theme) — threw her into primordial grief and led her to refrain from publicly addressing the death until this album.

“The only way, really, of getting over [grief] is to make it into something else,” Birkin says. “You’re lucky if you’re a writer or a director or if you’re an actress because you can make it into something else.”

Nearly 20 years ago, Birkin was diagnosed with leukemia. Despite its remission, the chronic disease has caused recurring health issues over the ensuing decades. She finished the vocals for “Oh! Pardon Tu Dormais” last February, planning for them to be demo tracks; shortly thereafter, the pandemic put the world on pause, causing her to largely keep the original versions for the album. The orchestra parts and instrumentation were recorded in late June, but by then, Birkin fell ill and required hospitalization. Rather than lament the sickness, Birkin savors the memory of the period, getting to the see the nurses’ faces and hear them describe the chaos of being a front-line worker battling the worst pandemic in a ­century.

“It felt like being in the First World War, where the nurses and doctors were all on the front line trying to save people from dying,” Birkin recalls of her treatment at a Paris hospital. “Twenty-year-old nursing students told me stories about zipping people up in body bags, six and seven a day. The great surgeons and doctors were mixing in with the nurses. It was a bit like being in a war zone. They would constantly get new ideas, and work with what little they had.”

As far as United Kingdom expats settling in France, Birkin’s association with her adopted homeland ranks up there with those of Oscar Wilde, James Joyce and the Rolling Stones’ brief early-’70s exile to avoid paying British taxes. She first moved there temporarily as a schoolgirl at 15, living on the same block as Edith Piaf, whose 1963 death caused a flood of mourners — including a pre-fame Gainsbourg — to shut down their street. The daughter of a debonair ex-World War II spy and the actress Judy Campbell, Birkin permanently decamped to France with her newborn daughter shortly after the 1967 dissolution of her marriage to Barry. By that point, she had already scored a small role in Michelangelo Antonioni’s seminal new-wave film, “Blow Up.”

The first meeting with Gainsbourg was a minor disaster. It was early 1968, and the son of Jewish Ukrainian emigres had become a superstar in France in the wake of his Eurovision Song Contest victory. Gainsbourg’s torrid love affair with Brigitte Bardot had ended unceremoniously when she decided to return to her husband, the wealthy German industrialist playboy Gunter Sachs. Disconsolate from the loss of what he believed to be his true love, Gainsbourg had retreated to his parents’ residence and filled it with oversized blown-up photos of the gorgeous French ingenue. His sultry duet with Bardot, “Bonnie and Clyde,” remained a few months away from becoming a canonical French crossover anthem.

Enter Birkin, a practically unknown actress auditioning for “Slogan,” a film in which Gainsbourg was starring.

“What did [Serge] see coming down the staircase? Me in a baby dress with a stupid fringe and an English accent, who couldn’t speak a word of French,” Birkin says, laughing. “There was a scene in the screen test about a separation, where I cried buckets. Serge thought it was really revolting to mix my separation with John Barry into the screen test. He had no time for that, but I noticed that he didn’t say that he didn’t want me in the film, which he could have done because he was the star.”

In their initial interactions, Gainsbourg was sarcastic and disdainful. But shortly after filming began, the director arranged for the cast to have dinner at the famed nightclub Chez Regine. The notorious “Gainsbarre,” his alter ego who had practically spit venom at her on set, was swapped for the more tender persona he carefully concealed. When the orchestra lit into a fast and jerky rhythm, Birkin attempted to drag him onto the dance floor. He blanched at the offer, and she danced alone. When they descended into a slower number, she successfully conscripted him onto the parquet.

“I noticed, to my joy, that he was clumsy,” Birkin says, breaking out into a smile at the memory. “He stepped on my feet and I thought, ‘How wonderful. A man who can’t dance. It’s just a miracle.’ From that second on, I realized it was all a sham, that he was actually shy, funny, sentimental, a joy to be with.”

As dawn approached after stops at a handful of other nightclubs, they ducked into a taxi, where Gainsbourg asked if he should drop her off at her hotel on the banks of the Seine. But she didn’t want the evening to end. By that point, Birkin had already fallen madly in love.

“I couldn’t get over my boldness,” Birkin says. “I thought he was going to take me to his parents’ or something, but he took me to the Hilton, where the man behind the desk said, ‘Oh, same room as usual, Mr. Gainsbourg?’ ”

Embarrassed by the clerk’s lack of discretion, Birkin vividly remembers the journey up in the elevator, crossing her eyes and making faces into the mirrored reflection of the doors. In the room, she immediately went to powder her nose, and came out of the bathroom to find Gainsbourg blissfully asleep on his back. Slipping a “do not disturb” sign into the door to keep it from locking, she hopped into a taxi, went to the drugstore and purchased “Yummy Yummy Yummy,” the novelty record she’d been dancing to earlier in the evening. Stealthily reentering the room, she poked the vinyl between his toes and returned to her own hotel.

“From then on it was all bliss,” she says, beaming.

To glimpse old photos of Jane and Serge is to enter a sophisticated netherworld that no longer exists, a glamorous fog of early-morning excess and possessed lust. The pair didn’t pose for shoots, they delivered propaganda from the gods. Jane, the original No. 1 stunner: plush lips slightly agape to reveal perfectly imperfect teeth, domino-thin and smoke in her marble blue irises, the prototype that Kate Moss ran with. Serge, a Roman nose and swarthy menace, eyes seductive and haunted, Lord Byron crooning lewd chansons.

Of course, there was ample controversy. In 1969 they released “Je t’aime . . . moi non plus,” an erotic colloquy that could’ve made Prince blush. Birkin whisper-sings with carnal reverie and eventually breaks out into orgasmic moans. Originally written and performed with Bardot, the actress insisted that Gainsbourg keep their version under wraps, lest it destroy her marriage. The Birkin and Gainsbourg version became the first foreign-language single to reach No. 1 in the United Kingdom. Several other countries banned it because of obscenity laws, which only amplified its outlaw infamy. (Forever the provocateur, Gainsbourg would eventually go on to make “Lemon Incest,” the scandal-inducing duet with their daughter Charlotte that dominated the French charts in the fall of 1984.)

But if a single work showcases their sui generis symbiosis, it’s “Histoire de Melody Nelson.” The “Lolita” of Gallic pop, it’s an album that distilled the couple’s nocturnal allure and supernatural charisma. Sex in the form of a symphony. Released on March 24, 1971, the conceptual song cycle of a poetic middle-aged lecher crashing his Rolls-Royce Silver Ghost and subsequently romancing the teenage Nelson, profoundly impacted everyone from Beck to Air, Portishead to Pulp. Apart from her laughter that Gainsbourg surreptitiously recorded while she was being tickled, Birkin appears only on “Ballade of Melody Nelson.” Nonetheless, it exists as the album’s beating heart, her voice delicate and filigreed, turning the syllables of the character’s name into a hypnotic incantation. It’s Birkin on the album’s immortal cover, too, wearing a red wig and four months pregnant with Charlotte. Hence, why her jeans are unbuttoned, a monkey covering the bump in her stomach. She would later place the stuffed animal for burial alongside Gainsbourg in his tomb.

“It wasn’t a hit, but it was always marvelous,” Birkin says. “Serge was always 20 years ahead of his time. He redeveloped the French language using English words as cunning as cold water. It was just an extraordinarily modern way of writing, and even as he got older, he intuitively understood how to be in step with the younger generations.”

This is perhaps why their partnership remains an idee fixe so many decades later. Birkin’s personal legacy is unmatched. She’s starred in a raft of memorable films for everyone from Jean-Luc Godard to Roger Vadim, as well as her former partner, Jacques Doillon (the father of her daughter, Lou, herself an acclaimed French singer-songwriter). Perhaps, most famously, Birkin sketched the original prototype for the Birkin Bag on an airplane sickness bag. She had complained to Hermes chief executive Jean-Louis Dumas that she couldn’t find a purse large enough to fit all of her things, and he vowed to create one for her. It’s since become one of the most coveted luxury items of all time, one name-dropped in countless rap songs. In later years, her philanthropic work has led her on humanitarian missions in Sarajevo, Rwanda and Myanmar. But the music, whether solo or with Serge, remains the most vital part of her creative impact.

“When she sings, everyone knows it’s Jane Birkin. She has a very unique style, both very fragile and really strong. She’s a survivor . . . amazingly bright and well-versed in poetry, books and cinema,” says Étienne Daho, the revered French musician who closely collaborated with Birkin on “Oh! Pardon Tu Dormais.” “For me, Jane and Serge were a symbol of freedom. Listening to ‘Melody Nelson’ as a teenager was like entering a new world. It’s a masterpiece.”

As far as the future, whenever regular life (or what’s left of it) is allowed to resume, Birkin looks forward to being able to perform these songs in person, as a way of allowing the pain of the past be alchemized into something else, art as a form of philosophers’ stone.

“I think you have to keep on searching,” Birkin says, reflecting on the meaning of this last half-century as an immortal. “I don’t think you can find things easily, at least for me.”

Reminded of the old Bob Dylan quote about an artist always being in the “state of becoming,” Birkin ponders what that means for her at this point.

“I don’t even know that I have a next evolution, personally,” she says, flashing a quick smile. “But I’m having good fun in this one.”