Have you ever thought what walking into a sweaty, dusty club on one of Star Wars’ desert planets would sound like? About what plays on the radios in the casinos on those Las Vegas-like planets? What do the merchants and miscreants of Tatooine listen to when they’re not working the moisture farms or fending off Tusken Raiders? Pondering questions like that has been Cody Matthew Johnson’s life for the past few years. The composer and artist has flirted with video game music before, with credits on Devil May Cry, Resident Evil, Bayonetta, and the cult indie Kurosawa-inspired side-scroller, Trek to Yomi. But for Ubisoft’s Star Wars Outlaws, he was tasked with making music for its seedy criminal underbelly.

“There is a limited scope of in-world musical expression in the original trilogy, and this was our opportunity to explore music canonically during that time in a much wider scope,” said Johnson, when I asked how much of a guideline the original trilogy provided for his work on Outlaws. “There are some ‘rules’, per se, to creating cantina music in the style of the original trilogy, and while this game does take place during that time period, we were encouraged to only be slightly influenced by the original trilogy cantina music.”

We’re all familiar with the Cantina band music that John Williams released in 1977 (a genre that was, regrettably, labeled “jizz” in-universe), but that’s mainstream, man. Matthew Johnson needed to go deeper, examining the dirt under the fingernails of Star Wars’ reprobates, and really tap into the culture of those both forgotten by the Empire and too dejected to join the Rebellion. He had to make alternate music for a universe we already know a lot about.

“The galaxy is far-reaching, there are canonically thousands (some say millions) of planets, and the in-world music over the last 40 years only scratches the surface of possibilities. The music for Outlaws wasn’t only about protagonist Kay Vess, and what she listens to, but more about the underworld she is existing in during the story – it’s not only the music enjoyed by the underworld subculture of Toshara, Akiva, Tatooine and Kijimi, but also the music created by that subculture.”

The result is a full album’s worth of tracks that clocks in at over an hour, and it represents more than 10% of all diegetic – or “in-universe” – Star Wars music ever made. To my ear, there are elements of ELO, Bonobo, Snarky Puppy, Kraftwerk and Ry Cooder in Songs from the Underworld; it flits between genres, leveraging weird and wonderful instrumentation. Matthew Johnson is as happy using a didgeridoo as he is a guitar – which makes sense, given that he’s a trained ethnomusicologist.

“All sounds, textures and instruments were on the table, including spider monkeys, seals, vintage carbonphone microphones, cimbalom, yaylı tambur, hulusi, shakuhachi, gamelan arranged in a drum set …” he says of this maximalism. “I was looking around every corner for inspiration to best represent these worlds and sometimes, yes, smashing gamelan, trash cans, didgeridoo and kazoo together sounded just right for Star Wars Outlaws.”

Matthew Johnson was “torturing himself” to avoid “zany alien music” playing in every hive of scum and villainy the player would pilot Kay Vess through. He made serious considerations, thinking about the sound of in-world instruments that the denizens of these worlds could physically play. He needed to consider “the timbral elements of different instruments, the emotions and semiotic denotations they evoked, and how they can be combined to create the sound of instruments that would have been created or inspired by the natural resources and culture of the world.”

For example, he explains in great detail, you need to consider the sympathetic, resonant buzz from a sitar, the aggressive attack of a plectrum on a saz and bouzouki, combined with the playing style of flamenco nylon string guitar and charango. All these remarkably specific sounds combine to get a unique melodic instrument sound that you’d get on a desert planet – as they do here, on the track If These Sands Could Speak.

To generate the spirit of collaboration and “we’re all in it together” attitude at the centre of so much alternative, underground music, Matthew Johnson needed a band. “It’s the joy of my life to be able to collaborate with my friends,” he explains. “It was a dream gig for every person I had the pleasure of bringing on to the project: musicians, engineers, instrument designers and more. The joy of performing and creating music is something we all share – it’s why we decided to dedicate our lives to this – and projects like Star Wars Outlaws that combine my history as a record producer, performing musician, recording artist and video game composer are the perfect vessel to make music that feels like you’re throwing a party.”

It does. The Star Wars Outlaws diegetic music complements the equally brilliant original score by Wilbert Roget II, providing a wonderful musical ebb and flow that you rarely see in open world games. The score is made to be heard by you, the player; the music on the radio, in the bars, that’s for Kay Vess. I think Outlaws might be one of the best examples of how in-game music can add texture and depth, even to a universe with as much history and lore as Star Wars.

“Outlaws is the perfect vessel to show how music can reveal narrative information without literally telling you,” Johnson says. “Kay walks down a hallway, turns a corner, you can hear a faint reverbed subwoofer thumping out kick drums; as we approach a door at the end of the hallway more elements of the music become audible, filling out the full frequency spectrum. Kay opens the door and the music floods over her as it reveals a two-level subterranean nightclub complete with band on stage, dancing patrons, dimly lit neon lights and a subtle haze throughout.

“Even before we arrive at the club, the music, and equally as important the music’s implementation in the game itself, reveal so much about our setting to the player.”

Songs from the Underworld is one of my favourite albums of the year so far. For me, it makes me feel what it’s like to be planetside on Star Wars, to really put myself in the shoes of a character who lives and breathes in these different atmospheres.

• Star Wars Outlaws is out now on PS5, Xbox One and PC; Songs from the Underworld is available on Spotify.