Michael Giacchino’s dark symphony for “The Batman” — from his brooding theme for Bruce Wayne to children’s choir for the Riddler and noirish stylings for Catwoman — is the year’s most talked-about score and among his most ambitious yet.

When Warner’s WaterTower label released a “Batman” track in late January, it racked up an astounding 2.3 million views on YouTube — the highest global streaming engagement the label had ever seen for pre-release from a score album. And interest has only grown in the weeks since the subsequent teasings of more Giacchino music and Friday’s release of the movie.

“Michael brought soul, he brought dread, he brought all of the emotional and atmospheric undercurrents that a movie like this requires,” director Matt Reeves tells Variety. “You almost can’t articulate what he brings — you can just feel it, how he expresses himself through music, how it relates to story.”

This is their fifth film together (including two “Planet of the Apes” movies, “Let Me In” and “Cloverfield”). Reeves brought the composer on board in 2019, even before he cast Robert Pattinson as Gotham City’s caped crusader. “The idea of doing that character, that world, is something I knew would resonate with him, just as when we were doing the ‘Apes’ films together, because we were both incredible fans from childhood.”

The Oscar and Emmy winner (“Up,” “Lost”) began writing and recording music based on script pages and conversations with Reeves. “And then I played it for the actors,” Reeves reports. “I played it on set. Rob was telling me it was one of the important tools in terms of getting into the tone of the character emotionally.”

Giacchino’s score is the symphonic equivalent of Reeves’ film, suggesting the haunted figure behind the mask amid the grim maelstrom of Gotham crime. His Batman theme contains two musical ideas: “Batman’s obsession,” an ominous, repeating four-note motif, and a Wayne theme “that has a kind of great melancholy that is really about being Bruce,” Reeves says.

His slinky Catwoman theme emerged from discussions of classic noir scores including Jerry Goldsmith’s “Chinatown,” Reeves reveals. “So we talked about incorporating those kinds of strings. Michael had written this beautiful theme for her that had almost gotten too purpley, with a sax and everything. So he stripped that back, but there’s a bit of a noir lilt to it, a slightly jazzy vibe.”

Most fascinating is the Riddler’s music, which involves a boy’s choir hinting at the mad villain’s troubled past. “Ave Maria,” Franz Schubert’s 19h-century vocal work, “was built in the movie’s DNA from the very beginning,” Reeves says, and he had Riddler actor Paul Dano sing it as a boy chorister.

He asked Giacchino for “a fun-house mirror version” of the piece to represent the grownup killer. “In an emotional sense, the Riddler’s still 10 years old. It would feel creepy… that kind of desperate boy’s voice throughout the whole movie. Michael wrote a very eerie version that has a spiritual connection to ‘Ave Maria.'”

Giacchino wrote all the main themes prior to shooting, Reeves says. “We edited with them, I started showing him the movie, and then he began writing again. I came to his house and we did what we always do, sit together, go through it and talk about scenes.”

At 2 hours, 55 minutes, “The Batman” is by far the longest film Giacchino has ever scored. He recorded with a 70-piece London orchestra and six-member boys choir over 12 days in October 2021. The orchestra — primarily strings, brass and percussion, with almost no woodwinds (just three clarinets) — was divided between Abbey Road’s Studio 1 and Studio 2, recording simultaneously with two conductors under COVID protocols.

Giacchino’s massive score clocks in at an hour and 56 minutes on the soundtrack album, which concludes with a 12-minute solo piano track, “Sonata in Darkness” based on the Batman theme and played by American classical pianist Gloria Cheng.

“What I love about him is, he’s such a funny guy,” says Reeves. “He’s like a jokester. You know all of his track titles are puns (“Escaped Crusader,” “For All Your Pennyworth”), which still drives me crazy to this day. But under all of that, he is the most sincerely emotional person. So it’s always a wonderful experience. It’s one of my favorite parts of making any movie. And music is a very powerful tool.”

The composer was unavailable for this story; he is reportedly off directing a television project for Marvel. His fifth film for the studio, “Thor: Love and Thunder,” is slated for a July 8 release, one of three more Giacchino scores expected this year. His “Jurassic World Dominion” opens June 10; Pixar’s “Lightyear” is due June 17.