HBO Max’s “The Staircase” marks the fifth collaboration for music supervisor Randall Poster and creator Antonio Campos. Poster says that the journey has helped build a musical rapport. When it came to finding the perfect needle drop moments for the true-crime series starring Colin Firth and Toni Collette, Poster looked to music that would help tell the story rather than rely on the musical tastes of the characters.

“The Staircase” retells the death of Kathleen Peterson, played by Collette, from a fall from a staircase in her home. Husband Michael Peterson (Firth) was convicted of murder in 2003. He was eventually released but to this day nobody knows exactly how Kathleen died.

Set around the events of 2001, Poster’s primary challenge was how to use music to tell that story as the story jumped back and forth in time within a short period. Poster says, “The challenge was how to use music to set the story in time, but also use music to reveal some of the less apparent personality components of various characters.”

“Jingle Bells,” “Rudolph the Red-Nosed Reindeer,” “Here Comes Santa Claus” by Gene Autry; Bing Crosby; Les Paul; Doris Day

Kathleen died on Dec. 9, which steeped the show around the holidays. That meant Poster having to find the right holiday tunes to play.

Says Poster, “The holidays are recurrent. We worked hard to be able to use real songs. There’s always the challenge of being able to afford all the music that you want to want to use, but we really were intent on specificity in terms of figuring out what would be their Christmas cheer? We were trying to have some fun when it came to the spirit of Christmas and use pieces to push certain emotions forward or to play as counterpoint. Towards the end, we used songs from the Phil Spector Christmas album, and songs that people often sidestep because of cost.”

“The Emperor’s New Clothes” by Sinéad O’Connor

Poster says, “This was one of the pieces that Antonio really wanted to have. We would sit down and play songs, but this one was one of the pieces that he felt was resonant. We were also trying to find some things that had not been used to death. We also wanted to find a female voice in the story at points. This was where Antonio has a very strong musical sense. He’s great with music and so were the editors. Antonio was here in New York so we were able to sit down and make decisions together. We could say, ‘I hate that. I love that. [In the case of this song], we really loved everything the lyrics said.”

“I Started a Joke” by Bee Gees

Says Poster, “This was one of the most challenging moments. The sequence is a montage that shows Michael working out, and cuts to the investigators working on the case and ends with the revelation that Michael was a part of this gay subculture that existed in Durham. We tried a lot of things and kept going back and forth. We had things that would work on one portion, but not another. So, that’s when we landed on Bee Gees. The song itself took you on a great journey, and the song is so emotional, that as an audience, it prompted certain emotional responses. The music itself was testing your reactions and preconceptions. But the song just did everything that we needed it to do. When it goes to the instrumental part, that was really one of the more vital musical moments in the show.”

“Out of the Blue” by Debbie Gibson

Poster says, “The pop tunes live among my guilty pleasures with Taylor Dayne and Debbie Gibson. Those were scenes where we could have put a library piece in there, but I fought for everything to be specific. The irony of Debbie Gibson playing in the gym when Michael cruising. Or when Kathleen is working out. The specificity of it made the characters feel more three-dimensional.”

Bad Romance by Lady Gaga

He explains, “With Lady Gaga, it was different because what’s happening on screen is such a startling dramatic moment. There’s the sense the music gives you a bit of comfort because you know it. But the raw violence that accompanies it is shocking. You think the song is holding your hand, but it’s taking you to this place that you don’t really want to go to.”