“Cobra Kai” Composers Discuss the Emotional Power of Scores

The hit series “Cobra Kai” returns to Netflix on December 31 for its fourth season, and the soundtrack’s composers, Leo Birenberg and Zach Robinson, are excited to share what they have been working on. 

“Cobra Kai” is a continuation of the “Karate Kid” film franchise, set in the present day, some three decades after the original movie. It follows the lives of the two archrivals from the 1984 film, Johnny Lawrence (William Zabka) and Daniel LaRusso (Ralph Macchio). 

Shortly after Birenberg and Robinson submitted their demo reels to the showrunners to audition for the scoring job, they got the gig. During an early post-production meeting with showrunners Josh Heald, Jon Hurwitz and Hayden Schlossberg, the composers learned how pivotal of a role the music would play in the series. 

“Jon’s sitting across the table and he was like, ‘You guys need to understand, this is my ‘Star Wars,’” Birenberg said, laughing as he recalled Hurwitz’s edict. 

At the time, Birenberg and Robinson thought the statement was the craziest thing they’d ever heard in a film or TV score production meeting. But as they started composing and submitting music, it became clear to them what Hurwitz meant. The showrunners were the biggest “Karate Kid” fans in town and had earned a Super Bowl of an opportunity to lead a continuation of the film franchise they loved so much as kids of the 1980s. 

The original score throughout “Cobra Kai” is meant to emulate the soundtrack playing in the characters’ minds. The composers said it’s the best way to approach a lot of the characters, especially Johnny. 

“It’s evident in our first episode where [Johnny] is beating the [expletive] out of all the teenagers in the parking lot,” Robinson said. “What is the musical score that he’s hearing in his head from his favorite martial arts movie from the late 1980s while he’s [fighting]?” 

The answer is a lot of 1980s rock and montage music from macho films of that era like “Rocky IV” and “Top Gun.”

While there are plenty of popular 1980s rock and synth hits, the original score Birenberg and Robinson created enhances the “Cobra Kai” story and spans several genres and decades.

“They trusted us with their giant baby and we were just so on board with everything they were doing on a spiritual level that it just made sense for us to all work together.”

The composers use the word “badass” to describe a sizable part of the soundtrack they created. But the music in “Cobra Kai” is not limited to machismo instrumentals. There are beautifully composed tearjerkers and even a few silly songs. 

Also peppered throughout “Cobra Kai” are well-timed remnants of Bill Conti’s original score from the 1984 film. That too was filled with classic synthesizers over training montages, glam rock and traditional Japanese music—especially in scenes featuring the late Pat Morita as Mr. Miyagi. 

The vast majority of the music in “Cobra Kai” are original compositions by Birenberg and Robinson that bridge 1980s rock music with Japanese-influenced instruments mixed in with electronic dance music. 

Scenes such as Daniel bowing at Mr. Miyagi’s grave feature a subtle gong, koto and a Japanese pan flute called a shakuhachi. Many training montages feature modern electronic dance music to cater to the younger generations of fans. One of the montage songs, “Slither,” includes rock keyboards that sound like a modern derivative of Van Halen’s song “Right Now.”

When Johnny retells his side of his high school vendetta to one of his students, the music features upbeat yet heartbroken guitar riffs and solos, reminiscent of Don Henley’s “Boys of Summer” and Bryan Adams’ “Summer of ‘69.”

“It hit home a little bit because Johnny was stunted and just kind of didn’t grow out of that [1980s] world, Robinson said. “So it felt very sincere to Johnny’s story. We’re hearing for the first time Johnny’s side of the ‘Karate Kid.’ We didn’t play it funny. We just kind of played it straight to how Johnny was feeling. That was something that the creators wanted.”

Creatively, Birenberg and Robinson are a great match for each other. Their voices sound identical, they finish each other’s sentences and laugh at each other’s quips. Birenberg specializes in wind instruments, having begun playing saxophone in fifth grade. Robinson is a left-handed guitarist who is a graduate of Wildwood School in West L.A. Long before that, he went to day school at Stephen Wise Temple. The two met after college while working for composer Christophe Beck on the soundtrack for “Frozen.” 

Birenberg, Robinson and their musical team did a live sold-out performance of their original score for fans at the Whisky a Go Go in 2019 after season two was released. Both composers hope they get to do another live performance at an even bigger venue after season four’s release.  

Unlike the showrunners, Birenberg and Robinson are 1990s kids. They’re both in their early 30s and said that their earliest recollection of the original “Karate Kid” was seeing it in pieces when it was often replayed on cable TV.

“It’s one of those movies that I’ve seen a hundred times but always starting in a different place, which I actually think is in a weird way really helpful for it to be in the fabric of cultural existence when you know every scene out of context,” said Birenberg.

In great films and TV shows, on-screen chemistry between characters is a crucial virtue. The cast of “Cobra Kai” have it. Behind the scenes, there’s also major chemistry between the showrunners and musical composition duo. 

“Before we write anything for any episode, we have a meeting with John, Josh and Hayden, which we call the spot session,” Birenberg said. “We go through the entire episode and we discuss every scene and the music and which emotions they want to hit.”

Longtime “Karate Kid” fans will notice throughout the series just how particular the showrunners are when it comes to using even the most miniscule of Conti’s 1984 score in “Cobra Kai.” It’s always done in a tasteful deliberate homage to a specific moment or feeling from the original film—never as arbitrary filler music. They are no different when it comes to giving nuanced direction to Birenberg and Robinson’s original scoring of the “Cobra Kai” soundtrack.

“It’s really just a totally perfect match,” Robinson said of their working relationship with Heald, Schlossberg and Hurwitz. “We’re very grateful for them to give us a shot too, because we didn’t have a ton of credits back then either. They trusted us with their giant baby and we were just so on board with everything they were doing on a spiritual level that it just made sense for us to all work together.”