It’s a pretty rare occasion when the director of a superhero movie sits down with the composer to talk about music and neither of them ever uses the word “action” or even “superhero.”

Instead, “Black Widow” director Cate Shortland and composer Lorne Balfe talked about the backstory of Natasha Romanoff and her sister, Yelena Belova. “Every conversation we had, right from the beginning, was about Natasha’s and Yelena’s heritage,” Balfe tells Variety.

“I wanted to write the music that Natasha and Yelena listened to when they were children. Russian folk music was their original soundtrack — what their parents would have sung to them, what they would have absorbed as children.”

So, in what may be the year’s most ambitious film score to date, Balfe enlisted a 118-piece London orchestra and a 60-voice choir singing Russian lyrics. And not just any made-up Russian words: Balfe adapted the poetry of such major 19th-century writers as Alexander Pushkin, Leo Tolstoy and Mikhail Lermontov for his texts.

While “Black Widow” is filled with the kind of action to which Marvel movie fans have become accustomed, many scenes concern issues of family or sisterhood, as Natasha (Scarlett Johansson) reunites with Yelena (Florence Pugh) and, reluctantly, their Russian-spy “mother” (Rachel Weisz) and “father” (David Harbour), the latter of whom doubles as the Red Guardian, Russia’s answer to Captain America.

“I wanted it to be authentic,” Balfe says from London of the score. “Originally, we were going to try and record in Russia. That was my plan with the choirs.” But a tight timeline resulted in Balfe employing London’s Metro Voices instead.

“The music of the Red Army was also a massive influence,” Balfe adds, referring to the famous Soviet-era choir that so passionately performed Russian folk and nationalistic music. “I wanted to give Yelena that Red Army robustness with her theme.”

Although Balfe (“Mission: Impossible — Fallout”) hails from Inverness, Scotland, at least part of his family ancestry is Russian, and he collected Russian art when he was younger. But “Black Widow” required delving more deeply into Russian music than he had previously.

“I started rediscovering [Igor] Stravinsky and [Anton] Rubinstein and [Alexander] Borodin, trying to understand where the music came from,” says Balfe. “What would Stravinsky have done if he was working these days and trying to write a Hollywood movie?”

In addition to themes for Natasha and Yelena, Balfe penned an ominous motif for Dreykov (Ray Winstone), the Soviet mastermind behind the Red Room that spawned an entire army of Black Widows, and for the sisters whose long-ago broken relationship must be mended for them to tackle the global threat that Dreykov still presents.

What listeners won’t find in the “Black Widow” score are clichéd Russian instruments like balalaikas or similar reminders from the “Doctor Zhivago” era. “My first thought was, I’m going to get 100 balalaikas and record them in Abbey Road,” Balfe says, tongue slightly in cheek, “but it didn’t fit the film. You can have the concept on paper, but it can become a parody.”

Instead, Balfe hints at Russian flavors with subtle, electronically created versions of such ancient stringed Eastern European and Central Asian folk instruments as the dombra, the gudok and the hurdy-gurdy.

What the composer did acknowledge, musically, was the female-driven story, by asking British-French classical guitarist Laura Snowden, Simple Minds drummer Cherisse Osei, beatbox artist Kimmy Beatbox, violinist Jasmine Flicker and vocalist Diana Artashesyan to contribute to the score.

The 118 musicians at Abbey Road in February 2020 are said to constitute the largest orchestra ever assembled at that fabled studio. “We were the last recording session at Abbey Road [prior to the London lockdown],” Balfe recalls. “Everybody knew that the studio would close in two or three days. There was a sense of sadness.”

To that symphonic sound, Balfe added a 40-voice male choir and a 20-voice female choir (the latter half classical, half gospel for a more contemporary sound). “We experimented a lot,” Balfe says. “We always did a take where there were lyrics and a take without lyrics. I think more time was spent on the pronunciation than doing the actual recordings.”