Knives Out” marks the fourth collaboration between composer Nathan Johnson and director Rian Johnson, having previously teamed up on “Brick,” “Looper,” and “The Brothers Bloom.” But their roots go far deeper than that: they’re cousins.

Nathan Johnson says he first heard about “Knives Out” over a decade ago. “He basically told me about the opening sequence,” Nathan Johnson says. “Through the years, as I was writing for other films, I’d occasionally come across this idea.”

It was only in 2018 when Rian Johnson sat down to complete the script and shoot the film. In most cases, the composer will see the film after its been shot. For “Knives Out,” Nathan Johnson was able to be on set in Massachusetts as it was being filmed. Aside from having the luxury of time to explore music cues and motifs, “it gave me the ability to explore,” says Johnson. “I was able to watch the actors perform, and it gave me the ability to get inside the world as it was being created.”

Another luxury for Johnson was working with an orchestra, a far cry from his work on 2005’s “Brick.” “We had zero budget, so it was about creating a score with what was at hand. We used wine glasses, filing cabinets and utensils for that score,” Johnson says. In 2012’s “Looper,” he was finding ways outside the box to turn a treadmill into a playable instrument. “It was fun to really play in the sandbox for ‘Knives Out,’ ” Johnson says. “We wanted to hit it from a fresh angle with real instruments.

The score for the film and its melodic motif was inspired by music of the ’50s and ’60s. “We loved using those traditional elements, but we still tried approaching things in interesting ways,” he recalls. That involved playing string instruments and having the musicians dig into the strings, “almost like knives.” “Knives Out! (String Quartet in G Minor)” sets that theme right away, a sharp sound that set the parameters for the score.

Knives, fittingly, feature a lot in the film. Family patriarch Harlan Thrombey (Christopher Plummer) dies early on in the film. The Thrombey clan clamor to seek their inheritance, but not before being interrogated in his throne of knives. For “The Thrombey Estate” cue, Johnson says, “I was thinking about Harlan. He’s the stream that everyone flows out of. He created this house for them all to live in. All the stuff in the house is stuff he’s written into his books.” With that, the score becomes a larger-than-life element, and Johnson says he used Hungarian scales. “It feels jazzy, but it’s leaning against notes that don’t feel exactly right.”

Johnson says his favorite music cue to write was “The Will.” We got to bring back the ‘Knives Out Quartet’ but with the support of a full orchestra,” he explains. “In that cue, the orchestra plays around with a gigantic string slide. That slide takes us into this unsettling craziness that begins to happen. ‘The Will’ is the shift in the movie. We break open the doors and we go for the throat.”