Editor's note: the following interview is edited for length and clarity.
No Film School: How were you approached for Wicked and what were those early conversations with director M. Chu like?
Simon Hayes: During my first conversation with Jon, he immediately shared his vision. “My instinct tells me this has got to be live,” he said. “We have two actresses who are not only phenomenal singers but also seasoned recording artists. This film is going to be massive—the sets, the scale, the choreography, the stunts, and the number of cameras I want to use. Do you think it’s possible to record live under those circumstances?”
It was a challenge, but collaboration is where solutions thrive. I reassured Jon that my team and I are used to handling such demanding scenarios. The key to success would lie in meticulous preparation and close teamwork with every department involved. It’s all about building symbiotic relationships during the months of pre-production. We would need to break down the script meticulously to identify the unique challenges each song presented, from costumes and dance movements to stunt rigging, manufactured wind, and shooting style. Working closely with each department, we’d address each of these factors to ensure that live vocals could be captured seamlessly.
Jon and I connected over our shared passion for musicals and the live process, sparking a collaboration based on mutual enthusiasm and understanding. His warmth and openness created an environment of supportiveness where creative ideas could flourish. “OK, final question,” Jon said, with a grin, “How many earwigs do you carry?” I responded, “75, but we have access to more if needed.” A smile spread across Jon’s face as he replied, “I think you understand just how big this is going to be!”
Simon HayesUniversal
NFS: How was this approach different from other musical to film adaptations you have done? What has changed since working on Les Misérables, for instance?
Hayes: On every film I mix I go into the process with a completely clear and open mind. I try to approach each project with a degree of naivety to ensure that I look at the narrative and shooting style of the director that has its own unique requirements, which helps me build a dedicated workflow and methodology that completely supports and endorses the film we are making. That being said, of course I use previous experiences and successes to influence the creative decisions I will make. I design new projects sound workflow from the ground up, taking advantageous techniques from previous films to help enhance my ability to support the director and cast on this new film. Wicked was, without doubt, the biggest and most challenging musical I have worked on to date and its unique story required a specific workflow.
On Wicked, we used a live keyboard to play into the actors’ IEMs for very emotional moments of live singing to give them freedom to take a moment and reflect as they performed in a way that a backing track won’t allow. The main music in Wicked has a strong heartbeat running through it. It is a rhythmic and modern score that needed to be adhered to, so for the majority of the music numbers we played back the fully produced backing tracks into the actors IEMs so they kept tempo locked. This is obviously incredibly important when their performance is based around large-scale choreography and everything happens on the beat. For this reason, instead of using only the tiny earwigs we used for Les Miserables when it came to providing in-ear monitoring (IEMs) for the cast of our Wicked, we knew we had to rethink our approach. Given that both Ariana and Cynthia are accustomed to full-range, cabled IEM systems for their live performances, Arthur Fenn (1st Assistant Sound) and I quickly agreed that the small hidden earwigs wouldn’t cut it. The bandwidth and audio quality of an earwig simply wouldn’t hold up, especially given the intricacies of the backing tracks mixed by the amazing Greg Wells. These weren’t as acoustically simple as a live keyboard from a frequency bandwidth perspective—these tracks were deep in bass and rich with musical complexity.
In live performance settings, IEMs allow artists to hear not only the backing track but also their own voices, often with a personal choice of customised reverb and mix that suits their needs on stage. We wanted to replicate that level of detail and support on set. To make this happen, we realised we’d need to collaborate with VFX, as any cabling or visible hardware in the actors’ ears would require a digital cleanup in post.
I reached out to VFX Supervisor Pablo Helman, and the collaboration was seamless from the start. Pablo, who happens to be a musician himself, immediately understood why our actors needed high-fidelity, full-range IEMs. Working with him, we developed a plan to use custom-molded, skin-tone-matched IEMs that could function in mono or stereo, depending on the scene requirements. Arthur then coordinated with the hair and makeup department who were incredible team players to discreetly hide cables, minimizing the need for VFX paint-outs, especially in wider shots.
To keep the setup as low-profile as possible, we focused on reducing VFX involvement to just close-ups or close mids, wherever possible. Any cast member who sang solo live vocals in Wicked had a choice of personal IEMs or earwigs for every scene they performed in, with their own blend of unique mix. Chorus and dancers used only earwigs, as their requirements were more for timekeeping and the need for absolute sonic excellence was outweighed by the cost of painting out hundreds of IEM’s. In the end, this solution allowed us to deliver the immersive sound quality our live singing actors needed without compromising the production's visual integrity—a true collaboration between sound, VFX, and the creative team.
Another technical advancement we used on Wicked, as a first, was completely digital microphones. During prep on Wicked, I was asked to beta test the new Schoeps CMD42 digital preamp, which allowed me to use my favourite MK41 super cardioid capsule but converts the signal to 24 bit/48KHZ digital within the microphone itself at the earliest opportunity. I was so impressed with the advancement in sound that I immediately decided to use the new product on all three of our Booms. We also moved onto the Sound Devices A20 mini transmitters that operate completely in the 24 bit/48khz digital domain. These two advancements meant that both boom and lavalier (personal) microphone systems used on Wicked were completely in the digital domain: a very tangible and real step forward in audio quality.
'Wicked'Universal
NFS: What did the preparation look like for a number like “I’m Not That Girl”? What are all of the factors you are taking into consideration?
Hayes: “I’m Not That Girl” is an incredibly emotional and fragile performance for Cynthia, and I knew this was a special moment where we had to be able to completely support her in everything she required to feel creatively comfortable and able to immerse herself in the performance without any concerns whatsoever in the technical aspect. She asked early on to be accompanied on live keyboard at the beginning of the song by our music associate, Ben Holder, to be able to express herself both sonically and visually without being completely bound by a uniform tempo.Of course, Ben kept complete musical integrity, but his accompaniment allowed Cynthia the freedom to explore her emotions as she sang which was a key benefit that the workflow brought.
From a technical standpoint, the live performance takes place in a number of different locations that all had their own acoustics, environmental noises, and sonic challenges. My job is to ensure that none of those issues affect the live vocal tracks I deliver and that Cynthia can perform unaware of any difficulties me and my team are facing technically. Cynthia always wore two DPA 4061 lavalier mics (left and right) which gave Nancy Nugent and John Marquis (Supervising Sound Editors), Jack Dolman (Supervising Music Editor) and Robin Baynton (Music Editor) choices when it came to head turns within the performance or the ability to cut from one track to the other if there was any momentary clothing rustle.This means they can deliver the very best comped vocal to Re-Recording Mixer Andy Nelson and Director Jon Chu in the final mix, but also keep those original stems available for Andy should he want to dig into them and try a different approach based on the way he is placing the music and FX around the vocal. We also, of course, boomed the performance wherever possible, but only when we could get in tight.
There is no room for acoustic width around the mic on a sung vocal, so the boom only played when it could deliver at the same sonic perspective as the lavs (i.e. in close ups). There was actually one section that could not be boomed at all as Cynthia sings as she walks through a tunnel of bushes. Luckily though, 1st AS Arthur Fenn’s lav placement was absolutely excellent and both lavs sounded superb through the whole sequence. Great lav placement was also due to a complete symbiotic, collaborative relationship with Cynthia’s costumier Carmen and for that we are incredibly grateful.
NFS: What was it like working with actors Cynthia Erivo and Jonathan Bailey in this particular number? Who else is playing a key role in what we are seeing on the screen?
Hayes: Cynthia and Johnnie are incredible talents but also completely understanding and appreciative of the teams in the background all working together to help bring the story they are telling to life. Filmmaking, especially musical filmmaking is all about teamwork and support. “I’m Not That Girl” was a masterclass in everyone on the film set working together to achieve something incredibly special.
NFS: What is the difference when it comes to a larger number versus one just as intimate?
Hayes: On Wicked, the larger numbers created their own technical challenges, authenticity is key, especially when bringing big, live musical performances to the screen. Me and my team faced this challenge head-on when tackling live chorus sequences on set. The goal was to capture not only the emotional nuances of the actors' solo vocals but also the raw, immersive energy of hundreds of background performers—each chorus meant to pull the audience deeper into the story.
We knew from the start that we would capture solo vocals live. They capture the actor’s individual emotions, the breathing patterns and vocal efforts precisely, preserving the physical and emotional energy of their performance. The solos contain the real time human nuances of the actor which match exactly what their character is doing physically as they sing. However, the chorus numbers, often featuring large groups moving in intricate choreography, were a different beast entirely. With dance-driven sequences, footfall, and acoustically challenging movements, capturing these big set pieces live needed their own dedicated workflows.
Despite these potential obstacles, we knew that live singing by the chorus, complete with occasional footfall and non-professional vocalists, contributed to a sense of unfiltered realism. A prime example is in “No One Mourns the Wicked,” where villagers join the main cast in song. Hearing hundreds of voices together, imperfect and unfiltered, brings a rawness that’s hard to achieve with a studio recording.
To make capturing these large chorus vocals achievable, we developed a unique approach.
The key lay in a mix of selective earwig distribution and immersive low-end reinforcement. With the guidance of music associate Ben Holder, the best singers in the crowds of up to 200 were assigned the 75 earwigs available, allowing them to keep tempo and lead others. Around the set, subwoofers provided a 45Hz ‘thumper track’ to set the rhythm, enabling the earwig-free performers to stay in sync. This subsonic track, falling below vocal frequencies, could then be removed during post-production without affecting the recorded vocals.
The result was striking. This technique allowed us to capture huge, authentic-sounding choruses in the natural acoustics of the film set, with depth and richness. The “No One Mourns the Wicked” was like a football chant in places: really intense. Hearing hundreds of background actors sing supported by 36 kilowatts of subwoofer power to drive the thumper rhythm was quite something.
The payoff was hundreds of voices, full of genuine emotion and physical effort, forming an immersive soundscape. This approach allows cinema audiences to feel the full weight of each live, impassioned chorus.
'Wicked'Universal
NFS: What did you take away from working on this project? And what do you hope fans take away from this experience, especially from a sonic perspective?
Hayes: Myself and my team took away an enormous sense of achievement, and our experience reinforced my opinion that the more regularly Production Sound and Post Production Sound teams can communicate before filming starts and create a singular, creative and symbiotic approach to the story we are telling, the better we will be as a singular team at delivering the director’s vision for the movie. For the cinema audiences around the world, I hope the passion and creative energy the whole film crew put into this amazing project leaves you feeling empowered and inspired. I believe that the live vocals we have delivered enrich the story we are telling and I hope you all feel that too!
Simon HayesUniversal 
'Wicked'Universal 
'Wicked'Universal
