Behind the Rousing Sound of ‘Blitz’ – with Paul Cotterell and James Harrison

Director Steve McQueen depicts the harrowing experience of The Blitz bombing of London in new his film Blitz – now streaming on Apple TV+. The story follows a mother named Rita and her 9-year-old son George. Rita decides to evacuate George from London – a trip he’d take with many other London children. But George escapes from the train bound for the countryside and he makes a perilous journey back home. Rita, who stayed in London to work in the factory and care for her father, has her own terrifying experiences of daily survival.

To help bring this tale to life through sound, McQueen turned to sound supervisors/re-recording mixers Paul Cotterell and James Harrison, who had worked with the director on his Small Axes series. Here, Cotterell and Harrison talk about their collaboration with director McQueen to build the chaotic bombing sequences both above ground and below in the bunkers. They talk about highlighting the humanity in the story, from supporting the feeling of camaraderie among the women working in the factory to George finding a friend in a guard named Ife, who tries to keep the child safe. They talk about sound editing and mixing for specific scenes, like George’s experience in the water-filled subway tunnel and his encounters with a band of thieves. Plus, they talk about working with Hans Zimmer score on Blitz, recording bespoke sound effects and loop group, and more!

Blitz — Official Trailer | Apple TV+

When did you get involved with Blitz and what did director Steve McQueen want you to tackle first?

Sound supervisor/re-recording mixer Paul Cotterell

Paul Cotterell (PC) & James Harrison (JH): We’d both worked with Steve before, most recently on his Small Axe mini-series. We worked on those through COVID and the lockdowns, which brought all sorts of challenges. This led us to mixing in small windows of time when restrictions were lifted, and we were able to get together. It was mostly just the three of us in the room and so we built up a great understanding of each other, how to work together, what Steve liked, and how he liked to work.

He first invited us to look at some scenes from Blitz while he was still shooting the film. They had a cutting room set up in the West End of London and I think they were on a few days break. We met with Steve and his editor Peter Sciberras and they showed us some of the bigger scenes they were working on. I think it was the scene outside the tube station with people fighting to get in, some scenes from the factory, and the Café de Paris musical scene.

We were shocked by the scale of what we saw! Steve had talked about the movie a bit, and we’d read the script, but we hadn’t envisaged the amount of extras in the scenes.

PC: There were a couple of scenes that they wanted me to clean up a little bit – some extraneous crew feet and things like that, but for the main part Steve wanted to start to build up some of the crowd voices.

So Rob Killick (crowd supervisor) and I did a couple of exterior group recordings that weren’t too specific: voices for the firefighters, people trying to get into the tube for shelter, people in the market, etc. We wanted to build on the tracks gradually rather than have a chunk of recording voices towards the end. So we “zoomed out,” did a lot of wild stuff, and then as scenes settled, we zoomed in a bit more, and a bit more, until at the end we did a pass of single voice recordings working specifically to lip-synced individuals.

The film opens during a bombing. Firefighters frantically try to contain the fires raging on both sides of the street. There are sirens. Buildings are falling. Bombs are falling. It’s chaotic. Then there’s this transition into a field of daisies and silence. Can you talk about your sound editing and mix on this scene? What were some of your challenges or opportunities for sound here?

JH: Right from the outset of our initial discussions with Steve, we’d agreed that we didn’t want to approach these scenes in a traditional, event-driven way. Steve didn’t want everything to sound neat and precise; he wanted the overwhelming chaos of these scenes to come through, and for the viewers to try and experience a small part of the carnage that people of the time would have experienced.

Sound supervisor/re-recording mixer James Harrison

We became aware very early on that intense sequences like this can have a very physical emotional response on a viewer, and it is something that we were all very attentive to in the test screenings – really watching the audience to see what they did (or didn’t) respond to. We would then go back and discuss what we thought was working, and what needed tweaking.

PC: I think I served as a sounding board for James during this process. He would focus intensely on small details, then call me in to run the sequence, and I could react with fresh ears.

I think it’s amazing what he’s achieved in that sequence — it’s so chaotic as an experience, yet there’s still clarity in what we hear and when we hear it. The sound helps guide us through the overwhelming visuals. I also love that Steve didn’t want music in there; it really puts the viewer right alongside the firefighters. Nothing separates us from the scene, which makes the cut to the upright piano being played in the next scene even more impactful.

As a mixer, I’m acutely aware of how quickly a mix can become overwhelming. Volume is the quickest and easiest tool to reach for, so we worked very hard to ensure this sequence remained engaging without pushing viewers away. We carefully managed the harsher frequencies that fatigue the ear while retaining the power and intensity the scene demanded.

For this particular scene, we would set aside a specific amount of time to work on it before switching to another area. This approach allowed us to come back fresh and remain objective each time.

The film follows a mother and her son. At times we’re with Rita, experiencing her perspective of the Blitz. And other times we’re with George in his experience of the Blitz (after escaping the train). How do these two experiences compare sonically?

JH: Steve spoke very early on about creating distinct perspectives for the main characters, especially George. What would a nine-year-old, experiencing something like this for the first time, remember or describe when looking back on it?

Steve spoke very early on about creating distinct perspectives for the main characters, especially George.

I remember working on the train station sequence, where Rita is preparing to put George on the train. We initially covered everything visible in the frame: every person speaking, footsteps, the hum of children, steam from the train, and so on. But then we wanted to shift into George’s world a bit.

In this perspective, the sounds of the children became more overwhelming, the slam of the train doors was heightened, and the lurch of the train was emphasized — not just as something he would have heard, but something he would have felt.

George goes on rounds with the guard Ife. It’s a quiet, intimate walk. Ife and George sing together before the air raid sirens start up. Can you talk about this quiet sequence?

PC: John Casali was the production sound mixer, and he delivered fantastic tracks, but this was the scene that he was most worried about!

He’d called up to say he was worried that he couldn’t get the crew movement/extraneous footfalls down sufficiently from all the cobbled streets because the dialogue is so intimate and delivered so quietly.

It was just too beautiful a performance from both of these characters to try to recreate it on the ADR stage.

John had positioned the lav mics exceptionally well, providing a good signal, and there was an additional mic in Ife’s tin hat, which turned out to be really useful. We carefully pieced together little bits of takes, cleaning up as we went. It was a meticulous and deliberate process. James slowly added clean footfalls, subtle cloth movements, and small details of accoutrements to help smooth the scene out.

It was just too beautiful a performance from both of these characters to try to recreate it on the ADR stage.

In the end, it became one of the quietest scenes in the whole film. George begins to open up for the first time to someone, and you really feel that warmth and humanity coming through.

How did you handle the sounds inside the bunkers? Did dir. McQueen have specific ideas for how to tell the story of what’s happening above, or did he leave that up to you?

— Can you talk about your sound work for the bunker scene with Rita and the others singing as the bombs fall overhead?

JH: The shelters were a crucial safe haven for Londoners during the Blitz, but there were never enough of them, leading many people to seek refuge in Tube stations out of desperation. The shelters became vibrant community spaces, where people shared food, drink, medical supplies, bedding, and entertainment. For us, capturing this bustling life underground — trying to persist despite the destruction above — was fascinating.

Dolby Atmos was invaluable for these sequences, allowing us to place sirens, bombs, cracking ceilings, and falling debris overhead with precision…

The film is deeply grounded in human experience, with most of the danger (e.g., bombs, sirens, water, planes, etc.) occurring above. Dolby Atmos was invaluable for these sequences, allowing us to place sirens, bombs, cracking ceilings, and falling debris overhead with precision while keeping the focus on the human elements within the bunker.

PC: For the singing of “Show Me the Way to Go Home,” John Casali managed to record several wild tracks from the extras, so we layered those up for depth. We EQ’d and added different reflections to them to get a sense of the space and the amount of people going back.

Steve wanted that sense of claustrophobia in those scenes, so these tight reflections from the vocals helped that, describing the low ceilings and brick walls.

Then for the foreground characters, we used ADR to give us that close detail layer. We were able to pan these singular voices around as the camera moved past.

Steve wanted that sense of claustrophobia in those scenes, so these tight reflections from the vocals helped that, describing the low ceilings and brick walls.

We also hear the people’s breaths and shudders as the bombs fall and the brick disintegrates to dust around us.

What went into the sound of the factory floor where Rita works? (There’s cheery music playing through the PAs mixed with machinery and women’s voices)

PC: These were important scenes for Steve, showing the women working in the factories. We get a great sense of the camaraderie of the women through the principal dialogue, having a laugh at the shop steward, and Rita’s friends teasing each other. Although it’s with some irony that we hear “Whistle While You Work” being piped in across the PA system!

Steve has a great way of bringing these scenes to life during spotting sessions. He’ll often start telling stories — some from his research about the era, and others from his own life growing up in London.

Steve has a great way of bringing these scenes to life during spotting sessions. He’ll often start telling stories — some from his research about the era, and others from his own life growing up in London. He’d talk about markets his mum used to take him to – the sounds, the smells, the atmosphere. It really helps us understand the feel he’s going for.

JH: For me, this scene had a personal connection, too. My family’s from Sheffield, which was a major steel-making town, especially during the war. I have vivid memories of those factory environments — the smell of burnt oil, the grease, the sparks from welding. Recreating that on screen was such a rewarding challenge.

…we did a lot of location recording (crowd and machinery) to replicate the space correctly.

Then it all comes down to layering. You’re painting with sound, really. There’s the movement, the music, the chains, the machines, sparks flying, crowd chatter, wire brushes, welders…it’s a bit of a dance through all the sounds you can put in, and we did a lot of location recording (crowd and machinery) to replicate the space correctly.

The factory montage was a great moment where Hans Zimmer’s score combined mechanical sounds to create a pulsating rhythm. I counterpointed this in the mix by moving and mixing some of the real machine sounds in and out of time with Hans’s music, which helped the ebb and flow of the scene.

Director Steve McQueen on set of ‘Blitz’

George meets Jess, and she brings him to a band of thieves led by Albert. George is forced to do bad things, like raid a bombed-out jewelry store. Can you talk about your sound work for this scene?

JH: This scene sticks with me. I’d done a design pass on this sequence, again wanting to create a slightly more heightened and eerie environment that George himself might have remembered. I used tones created from broken pianos and slowed-down wood creaks to help create a mood.

I used tones created from broken pianos and slowed-down wood creaks to help create a mood.

Then we got some of Hans’s music – a first demo for this sequence. It was relatively early on in the post process, before we’d even had proper conversations with Hans, and I have to admit I was slightly nervous about putting it in the timeline – wondering about how much of my work I’d have to change and modify. But the music fit like a glove. It was seamless with the design ideas I was doing, and I knew then that we were all completely on the same page – with the same feelings and goals for this project. I have been lucky enough to have worked with Mr. Zimmer a few times in my career, and I hope I will again soon – he is a consummate professional and a formidable artist.

Director McQueen on set for the Café de Paris scene in ‘Blitz’

George is then forced to loot dead hotel guests. Can you talk about the sound inside this location?

JH: There is a reverential tone to the acoustics in this scene. Dialogues and crowd were kept subdued and muted, and foley and movement had very few transients. We leaned into very dry-sounding effects – like, wood and dust – and this helped the gang’s sounds (breaking glass, flesh sounds for ripping jewelry from fingers, etc.) sound slightly out of place in this environment. This subtle dissonance helped underscore the moral and emotional wrongness of the scene.

There is a reverential tone to the acoustics in this scene.

Hans Zimmer’s score was masterfully integrated here. He reworked the trumpet theme from the band — a piece historically played during the bombing of the real Café de Paris — by slowing it down and shifting it to a minor key. By pitching the trumpet’s lingering notes slightly downward, he evoked the ominous memory of bombs falling, tying the scene to its tragic historical backdrop.

It was a quiet scene, but in my view extremely effective, and one that took quite a while to mix until we were completely happy with it.

What went into your sound work for the subway station flooding sequence? What were some of your challenges or opportunities for sound here? (I like how the space becomes less reverberant as the water level rises…)

JH: Working with water can be very challenging because, by its very nature, it is essentially white noise, so trying to create movement, dynamics, and space without losing intensity and interest can take quite a while.

As with the fire sequence at the beginning, our approach was one of constructed chaos, so mixing all these elements together was just a question of time and persistence, chipping away until we were happy with the shape.

…production sound mixer John Casali did a fantastic job in this scene. How he was able to capture some of George’s breaths in amongst all that water and carnage is beyond me.

I have to say at this point that the production sound mixer John Casali did a fantastic job in this scene. How he was able to capture some of George’s breaths in amongst all that water and carnage is beyond me. We were extremely lucky to have had him on board.

Likewise, Hans’s score here was genius, really pinpointing the frequencies that he could musically inhabit, and within those really creating a sense of panic and tension.

There’s the cool transition of the planes flying over the ocean. What went into your sound design for this?

JH: So this section is a bookend from the beginning of the film, because after the starting fire sequence, we cut to the black and white “water reflections” shot, which then cuts to the daisies. At the end of the film, this shot pans out, and we realize what it is that we are looking at as the bombers fly past. Steve wanted to have a distinct sonic identity for this “abstraction,” but one that fits into the sonic arc of the story.

I recorded metal fins, pipes, and rods I held out of my car window as my wife drove down country lanes.

Since the film was so historically accurate in so many ways, I didn’t want the sound to feel synthetic or processed, so my starting point was really simple: wind and metal. I recorded metal fins, pipes, and rods I held out of my car window as my wife drove down country lanes. I then combined these recordings with various wind sounds, turning to outboard gear at times to create speed and movement (I love granular delays!). This coupled with various distortions and EQs helped create the tonal fundamentals of what we ended up with.

With sections like this, it’s really important to try and schedule in “play time.” Don’t set a goal or deadline, just have time allocated to do what you really enjoy, experiment, and have fun!

What was the most challenging scene for the mix? Or, was there a scene that went through the most iterations on the dub stage? Can you talk about some of your choices on the dub stage that helped to tell the story best?

PC & JH: The most challenging were the fire and flooding sequences, and it was really because of the intensity of the scenes. We could only mix these sequences for an hour and a half max before becoming fatigued. We would then have to put it to one side and come back either later in the day or the day after with fresh ears. They very much evolved; with every pass, we would hone in or polish some detail or other, and slowly, but surely it all came together.

What have you learned while working on the sound of Blitz‘?

PC & JH: Working on Blitz really highlighted how important collaboration and research are when it comes to creating a soundscape that’s both authentic and emotionally impactful. It also made us appreciate just how powerful silence and subtlety can be — how they can really build tension or bring out those quiet moments of connection.

A big thanks to Paul Cotterell and James Harrison for giving us a behind-the-scenes look at the sound of Blitz and to Jennifer Walden for the interview!

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