Few animated films this year have connected with audiences the way “Kpop Demon Hunters” has. Since its release, the Netflix hit has remained a Top 10 fixture and gone on to become the most-watched film in the platform’s history, an unusually organic rise driven by how strongly its hopeful tone has resonated at a moment when the real world often feels anything but. By now, even viewers with little attachment to K-pop or animation have likely encountered the phenomenon, as the real-life singers behind Huntr/x have become a constant public presence, from late-night talk shows to major live stages including the Thanksgiving Day Parade, Christmas Day NFL halftime programming, and New Year’s Eve broadcasts. That visibility has helped turn the film into a shared cultural moment rather than a niche hit.
At the center of that musical impact is “Golden,” the film’s breakout anthem and sole Oscar Best Original Song submission. The decision to campaign a single track reflects the confidence behind a soundtrack that quickly escaped the screen, with multiple songs breaking into the Billboard Top 10. For songwriter Mark Sonnenblick, the moment represents the culmination of a carefully built creative partnership rather than a sudden crossover hit.
Sonnenblick joined “Kpop Demon Hunters” in early 2023 as the filmmakers refined their approach to music, pushing away from conventional animated numbers and toward songs that could function as narrative engines. From the outset, that work was closely tied to his collaboration with EJAE, whose decade-long experience inside the K-pop trainee system helped shape the film’s emotional core. EJAE also voices the singing performances of Rumi, giving the songs an added layer of intimacy between character, performer, and story.
“The filmmakers realized they specifically needed songs that functioned more like musical theater storytelling,” Sonnenblick recalls. That mandate placed unusual weight on lyric structure, point of view, and emotional specificity, demanding that each song advance character and plot rather than simply amplify energy.
Together, Sonnenblick and EJAE developed a shared creative shorthand rooted in trust and restraint. “We trusted that if one of us didn’t feel good about something, it didn’t stay in the song,” Sonnenblick says. “Ultimately, you’re looking for that Venn diagram where all your sensibilities overlap.”
That collaborative loop extended across departments, with songs cycling between music, animation, and editorial as storyboards evolved and screenings clarified what the film needed. “Some songs went through an exhausting amount of revisions,” Sonnenblick admits, “but seeing how they eventually supported the movie was exciting.”
In the conversation below, Sonnenblick breaks down that process in detail, from shaping “How It’s Done” as a narrative entry point to the long evolution of “What It Sounds Like,” and the significance of watching EJAE finally step into the spotlight. It’s a craft-driven look at how “Kpop Demon Hunters” turned its soundtrack into story.
Awards Focus: Mark, thank you for joining us. It was a pleasure meeting you at the SLC event, and I’m glad we could connect during the holidays. To start at the beginning, when did you first join the “Kpop Demon Hunters” project?
Sonnenblick: I joined in 2023, likely around March or April as we were pushing into the spring.
AF: At that stage, a significant amount of work was already underway. Were the tracks already written, or were you essentially starting from scratch?
Sonnenblick: It was a bit of both. Some elements existed—”Soda Pop” was there—and as often happens with films, they had some comp and temp music in place. There were also older versions of songs that we ended up building nearly from the ground up.
I reviewed about 35 to 40 minutes of storyboard that, while not the full story, provided a clear sense of the vision Maggie Kang and Chris Appelhans wanted to tell. They had clear ideas about where the songs should be and what they needed to accomplish. The filmmakers realized they specifically needed songs that functioned more like musical theater storytelling. That is why the executive music producer, Ian Eisendrath, reached out to me. For example, on “Free,” a draft existed that I came in to redo the lyrics for. Most everything else was written from scratch, though some pieces of old material remain in the final versions.
AF: For those of us who aren’t songwriters, when you say they brought you in for the “musical theater element,” does that refer primarily to the lyrics, or does it involve the melody as well?
Sonnenblick: A lot of it is lyrical, but it is also structural. In musical theater, the music is caught up in the emotional moments and the intensity of the scene, which involves both melody and lyrics. As the vision for the film became clearer, we collaborated to ensure the soundtrack supported that vision.
What I love about these projects is coming in and meeting new collaborators. I did not know EJAE, Black Label, Stephen Kirk, or Jen Andrews before we did “Free” and “What It Sounds Like,” but the beauty of songwriting is how collaborative it can be.
AF: With such a diverse group of creators involved, how did that collaboration actually function when you started mapping out specific story beats into the music?
Sonnenblick: The process usually starts with the filmmakers. Maggie Kang, Chris Appelhans, and Ian Eisendrath would lay out what a song needed to accomplish. They would provide pages of brainstorms, story beats, or even monologues. We would then work to translate those into specific musical goals: the song needs to do these six things, or we have to hit this beat in the first 30 seconds.
On “Kpop Demon Hunters,” the process was also influenced by how K-pop works. For songs like “Golden,” “Your Idol,” and “How It’s Done,” the vibe and track would come from Black Label first to establish the energy. Once the directors and Ian greenlit the track, EJAE and I would collaborate. She handled most of the melody to ensure it was a true K-pop song, and I would bring in the lyric ideas. We edited each other to find a balance that functioned as a pop song while hitting the emotional and character beats required for the film.
AF: If you look back to when you first started this project, did you have any inkling of what “Kpop Demon Hunters” would eventually become?
Sonnenblick: I don’t think anyone realized it would be loved to this extent. However, even from that initial 40 minutes of storyboard, the visuals and character designs were incredible. Nothing was animated yet, but you could tell the final product would be stunning. Sony has a history of pushing the boundaries of what is possible in animation, so I was excited about that aspect.
For me, every project starts with the story and the characters. Rumi’s journey—her struggle with being caught between two parts of herself and learning to hate a part of who she is—was there from the beginning. It resonated with me immediately. Her journey is universal, almost like a fable. From a songwriting perspective, the challenge is finding the universal truth within very specific character beats.
Even with the slightly ridiculous premise of killing demons, Maggie Kang and Chris Appelhans wanted to make something deeply human. I knew right away I wanted to be a part of it. Working with some of the best K-pop writers in the world to see how that collaboration would look was a huge draw. As the movie came together, it was something we all loved. You often make things you love that don’t necessarily break through, so seeing fans respond through word of mouth has been incredible. You know that kind of success is never a given.
AF: How immersed were you in the world of Kpop before taking on this job?
Sonnenblick: I had almost no exposure to it. I knew of BTS and had heard a few BLACKPINK songs, but only in the most basic way. Part of this journey was getting to know the Kpop canon and hearing some amazing music. I felt lucky to work with collaborators who are literally making this music at the highest level.
AF: Did coming in as an outsider to the genre change how you viewed your role in the songwriting process?
Sonnenblick: My job was to support their vision of what these songs should be, just as we were all supporting the directors’ vision for the film. I love songwriting by myself, but the chance to be part of something bigger than yourself is exciting. Everyone pushed each other because of the unique mashup of styles in this movie. It resonated because it was something different than anything done before.
AF: You collaborated with some of the top Kpop songwriters in the industry. Was there a level of “healthy tension” that led to surprising or better outcomes? Can you give an example of a song where the final version shifted significantly from your initial vision?
Sonnenblick: Part of the process is the push and pull of people working together. There was nothing intensely personal, but my approach—which many pop songwriters share—is based on the belief that combining perspectives leads to a better result.
You always go in with ideas you love or lines you want to fight for, but you also realize you are collaborating to fulfill what the song needs to be. I might come in with pages of lyrics or rhythmic ideas while EJAE brings in melodic concepts. We trust that if one of us does not feel good about something, it does not stay in the song. Ultimately, you are looking for that Venn diagram where all your sensibilities overlap.
AF: Beyond the songwriters, how much did the filmmakers influence those specific creative choices?
Sonnenblick: That is the other major factor. There are rounds and rounds of notes with Maggie Kang, Chris Appelhans, and Ian Eisendrath. It is not just the songwriters collaborating; there is constant back and forth with the directors. EJAE might say a lyric is not “poppy” enough, or I might suggest a more rhythmic section to fit Zoe’s backstory into two lines.
But we cannot be too precious about those choices because the song then goes to Maggie and Chris. They see how it sits with the animation and the story screenings. They might come back and say a specific bridge is not working because the plot is changing or they are discovering new things about the characters. That Venn diagram of three people suddenly becomes a Venn diagram of six or seven.
Some songs went through an exhausting amount of revisions, but seeing how they eventually supported the movie was exciting. There is healthy tension because everyone is focused on serving the film. Some amazing songs were cut, not because they were bad, but because they did not support the movie as strongly as others. You have to learn quickly not to be precious; you fight for what you care about, but your job is ultimately to serve the film.
AF: Part of the charm of “Kpop Demon Hunters” is the element of parody. How did you balance that humor to ensure the movie remained inspirational without leaning too heavily into being “Soda Boy-ish”?
Sonnenblick: It is a huge testament to Maggie Kang, Chris Appelhans, the animators, and the entire filmmaking side. They struck a balance that defines the movie: incredible jokes and gags sitting alongside a very real, emotional story. They did a genius job of hitting a variety of emotions and styles in this mashup.
I did not work on “Soda Pop,” which is probably the closest the film gets to parody. For the songs I did work on, I was not really thinking about parody. Sonically, we wanted them to sound very real, even when we used a throwback sound. We were never poking fun at the genre. Lyrically, it was less about a meta parody of Kpop culture and more about the fact that these girls are just funny. In pop songs, lyrics deliver the character’s attitude. Here, you are balancing their public personas with their private lives in a beautiful way.
AF: How does that character attitude translate into the specific lyrics for the different members of the group?
Sonnenblick: Look at “How It’s Done,” which is the first song. It had to set up how these girls sing, rap, and communicate with each other. We gave them specific attitudes. For Zoe, we have lines like “fit check for my napalm era” or “I know I ramble, but when she my words, I go Rambo.” It is a true reflection of her character—she is wordy and fills journals with lyrics, but this is how she expresses herself in a badass, witty way.
The jokes are woven into the fun of the lyrics, like how Mira raps “now that’s how I’m getting paid.” “What It Sounds Like” had to be entirely from the heart and on-story, but even there, the humor came from the characters being funny people. We wanted to give them lines that made them pop stars you would actually want to hang out with or see in concert.
AF: Once the actors and singing voices were cast, did that influence the creative direction of the songs?
Sonnenblick: Sonically, it did, but the songs were basically written by the time EJAE and Danny Chung accepted their roles. Danny, who wrapped “Baby Sacha,” actually wrote “Soda Pop,” and we all collaborated on the raps in “How It’s Done.” He had been involved in several demos already.
The song and movie approval were largely locked in by the time the singers arrived. However, their vocal takes and energy definitely defined the characters through sound. EJAE is an incredible vocal producer—her demos are actually out there—so we rarely needed to bring in separate demo singers. While the characters were shaped by their performances, the lyrics and melodies remained consistent.
AF: Which song proved to be the most challenging to finalize?
Sonnenblick: It varied. “How It’s Done” was a long journey because it serves as the opening. You are trying to hit so many markers to bring people into the world. If that song doesn’t work, people might just turn off Netflix. We had to ensure the energy and storytelling got the audience on board with the girls while signaling exactly what kind of movie this was.
AF: Aside from the opening, was there a specific track that underwent a significant evolution during production?
Sonnenblick: The one that took the longest was “What It Sounds Like” at the end. We spent more than a year trying to find that song because it is a vital story beat. As the final climax of the movie shifted and evolved, the song had to change with it. Stephen Kirk mentioned he had more than 100 different bounces of that track.
There were versions where the character Jinu had a rap, or where we tried a “Free” reprise. Early on, the song was even called “Kaleidoscope” before we narrowed the focus to the connection between these three girls and their voices. EJAE did a lot of the vocal arrangement, figuring out how to build the emotion from an a cappella start.
I am really proud of it because the story is told almost entirely through that song. The filmmakers and the studio were very supportive; when something wasn’t working, they encouraged us to find the solution in the music and lyrics. A good example is “Do You Sacrifice.” We originally had a big “Free” reprise there, but it was the wrong energy for such a tender moment, so we moved to dialogue. But for the finale, the girls coming together and defeating their demons happens within the music. Landing that was very difficult.
Here is the refined version of this section. I have tightened your questions and smoothed out Sonnenblick’s responses, focusing on the technical collaboration between music and animation, as well as the personal narrative of his work with EJAE.
AF: With so many iterations over a year, what was the back-and-forth like between your music team and the animators and editors?
Sonnenblick: That process is really handled on the filmmaking side, which acts as the conduit between the music and the visuals. We deliver a draft of a song, and there might be some back-and-forth for a week or two. Then, it lives with the filmmakers and the technical music team for months. During that time, they experiment with the soundscape. Because we deliver stems, they can try a section a cappella, add strings, or bring the drums in later to see how it fits the storyboarding.
Sometimes they will cut a section or have Maggie Kang or Chris Appelhans talk over it. The song sits and “bakes” with the footage for a while, then it comes back to us with notes on what is working or why a section needs to be shorter. We might then have a very tight deadline—sometimes a week—to deliver a new version of a song we wrote months prior.
AF: Can you give an example of how that “baking” process improved a specific song?
Sonnenblick: For “Golden,” we sent a verse and chorus and got initial notes. A few months later, the filmmakers realized the bridge was a key moment where Rumi needed to “step out” of the song and sing from her heart. Calibrating that was tricky; it required that month-long gap where they tried it in animation and screenings to see exactly how it needed to be shaped. That was the standard journey for most of the songs.
AF: You are often paired with EJAE at events. Given her ten-year journey as an idol trainee without a debut, what has it been like seeing her finally have this moment?
Sonnenblick: It is incredible and beyond deserved. We clicked immediately. EJAE has an extraordinary voice, but she is also brilliant at vocal production and arranging harmonies. She was one of my primary gateways into Kpop; she would make me playlists and explain when something I wrote felt “out of genre.” That gave me a much deeper appreciation for the theatricality of the genre.
Beyond her artistry, she knows the culture and the fandom so well because she lived through the system. It was important to her that we respected the legacy of Kpop while making something for the fans. There is so much of her own story in Rumi’s story. When it was decided she would actually sing for Rumi, it felt right. We had literally written these songs for her voice. To see her dream finally happen, and to see her glow out in the world these past few months, makes me so proud of her. Her journey is just beginning.
AF: Congratulations on the three Grammy nominations! Given that success, why do you think the Academy only nominated one song for an Academy Award? In my opinion, “Kpop Demon Hunters” had at least two or three additional worthy contenders.
Sonnenblick: Thank you. To be candid, Netflix only submitted “Golden” for consideration, so it was never a question of whether other songs would make the shortlist. That was the strategy for the Grammys as well; they wanted to get people to really rally around that one song. It was the only track put out there in contention for these awards.
AF: That is an interesting approach, likely to avoid splitting the votes—similar to the “White Lotus” effect.
Sonnenblick: Exactly. They just did not want to split the votes. They would rather have the focus remain on this one specific thing.
AF: Thank you so much for your time, Mark. One last question from my daughter: everyone wants “Kpop Demon Hunters 2” immediately, but realistically, how long does a project of this scale take to ensure that same level of quality?
Sonnenblick: I do not know the exact answer because so much of it depends on the filmmaking side. The soundtrack is a major component, but the vision for the storytelling and the animation itself takes a long time. It is a question for the directors and the animation team. I believe the official announcement for the sequel mentioned 2029, so it is a long-term journey.
AF: I will certainly double-check that date! Thank you again, Mark, and have a wonderful holiday.
Sonnenblick: You too. Thanks for chatting; I really appreciate it.