Defying Gravity: The Audio Wizardry of Wicked's Live Vocals

Summary

---

Episode Overview

Podcast: Twenty Thousand Hertz
Host: Dallas Taylor
Episode: Defying Gravity: The Audio Wizardry of Wicked's Live Vocals
Date: November 19, 2025

This episode dives deep into the revolutionary approach to recording live vocals on the set of the movie adaptation of Wicked. Host Dallas Taylor and guest Simon Hayes (Production Sound Mixer) explore the technical and artistic challenges of capturing live singing amidst the chaos of filmmaking, how their team defied industry norms, and the magical results their innovations unlocked.

---

Key Discussion Points & Insights

The Challenge of Movie Musical Vocals

• Industry Norms: Most movie musicals pre-record actors’ singing in studios, then have them lip sync on set due to noise and logistical issues. This disconnect can often be heard in changes in vocal tone and performance energy.

  • “On Old School Musicals, they weren’t singing live, they were miming to a playback track.” — Simon Hayes [03:24]

• Wicked’s Bold Choice: Wicked’s filmmakers insisted on live, on-set vocal performances for authenticity, demanding unprecedented audio technique.

  • “What I wanted to do in Wicked was… we don’t want to hear this transition between singing and dialogue because there isn’t a transition because it’s all live on the set.” — Simon Hayes [04:40]

Capturing Pristine Audio in a Chaotic Environment

• The Role of the Production Sound Mixer: Simon Hayes describes his central responsibility: to ensure the “cleanest vocals possible” survive to the final cut.

  • “If I have a bad day at work… the actors will have to come in, they’ll have to re-record their vocals.” — Simon Hayes [06:10]

• AVOIDING ADR: Automated Dialogue Replacement (ADR) is common but rarely matches live performance authenticity. The episode details its pitfalls, including tonal disconnect and lack of natural reverberation.

  • “We never get the actors back in together to ADR their piece… there will almost be a disconnect for the actor.” — Simon Hayes [07:02]
  • “Someone that doesn’t understand filmmaking… may just be living, looking at the actors, facial expressions, listening to the tonality of their voice and thinking, I don’t trust this.” — Simon Hayes [07:38]

Technical Innovations: Mics and Mixing

• Consistent Close Miking: To avoid tonal shifts, dialogue was recorded as intimately as the singing, often using lavalier microphones, even when this required visible placement and later digital removal (VFX).

  • “I wanted that close up dialogue so there was no transition into the singing voice.” — Simon Hayes [09:05]
  • “If it’s a bit of velvet, a bit of chiffon, a bit of silk, it’s either going to be rustling or it’s going to sound muffled… so we just put the microphone straight on the outside and it was removed in post.” — Simon Hayes [11:06, 11:17]

• Boom Mics as Backup: Multiple boom mics were still used for flexibility, sometimes “jostling for position” just out of frame and occasionally painted out in post-production.

  • “Even if Ari and Cynthia are singing absolutely nose to nose… we always had two boom mics.” — Simon Hayes [12:24]

• Presenting the Director with Choices: Hayes recorded multiple isolated tracks (from both lavs and booms), providing editors with editorial flexibility in post.

  • “I’m presenting him with choices… how he wants the final film to sound.” — Simon Hayes [12:59]

Preserving Performance Energy in Duets

• Instead of asking actors to “mime” during the other’s close-ups (for clean solo tracks), both leads always sang live, capturing the genuine emotional dynamic between them.

  • “Every single time, it was like their vocals meshed. Something very, very magical happens when those two start dueting together.” — Simon Hayes [14:32]

• The audio team prioritized capturing that immediacy, even if it meant more work in post.

  • “You can sing over each other as much as you want to. We will work it out as best we can in post production.” — Simon Hayes [14:32]

The Wicked Ensemble & Thumper Tracks

• Chorus Vocals: Large ensemble numbers blended live recordings (for realness and raw energy) with perfectly sung studio overdubs (using singers from the Broadway show).

  • “There was this very, very raw and real part of the way that they were performing that sounded like they were angry villagers.” — Simon Hayes [21:33]

• Foley Realism: A “thumper track” (a deep, sub-bass rhythm routed only to dancers’ in-ear monitors) enabled them to record synchronous movement and stomping—without any musical leakage.

  • “We would take the sub bass… the sweet spot was 38 hertz... get them all doing their stamping… in tempo to the track.” — Simon Hayes [22:52, 23:16]

In-Ear Monitors and VFX Camouflage

• Discreet Monitoring: Cast wore color-matched in-ear monitors to hear the accompaniment. For close shots, IEMs were painted out with VFX.
  • “We basically got that exact color match for her [Cynthia’s] IEMs.” — Simon Hayes [25:10]

Flexible Tempo: Bridging Live Emotion with Backing Tracks

• Allowing Expressive Timing: To facilitate emotional delivery, soloists sometimes sang along to live keyboard accompaniment (in IEMs), with pre-recorded tracks crossfaded in at certain musical cues.
  • “We allowed the actors to go off tempo with a keyboard, but still knowing that at a certain point the drums and the bass was going to come in.” — Simon Hayes [26:37]
  • “Her first verse and a half was completely freeform… you can just feel her emotions.” — Simon Hayes [27:47, referring to Cynthia Erivo’s ‘I’m Not That Girl’]

The Ultimate Test: “Defying Gravity” Goes Live

• Flying & Singing: The episode’s climax details the most daunting scene: Cynthia Erivo singing “Defying Gravity” while performing aerial stunts, amid wind and wire rigs.

  • “What are you going to do about defying gravity? Cynthia’s flying through the air. Surely she’s going to lip sync to that.” — Simon Hayes [16:02, revisited 29:33]

• Silent Wind Innovation: Wind effects were created with ducted, offstage fans and piped air, minimizing mic noise that would traditionally force ADR.

  • “All I could hear was a kind of broadband shhh, which… can be removed from the vocal pretty easily these days.” — Simon Hayes [30:48]

• Set-Wide Quiet: Even hydraulics for stunt wires and camera tracks were silenced for clean vocals.

  • “We just all pulled out every single stop to make what would normally be an actual sequence in a superhero movie… quiet.” — Simon Hayes [31:47]

• Cynthia’s Confidence: When asked if she wanted to sing live while flying, Cynthia Erivo simply replied, “Of course I’m singing live.” [32:40]

• Result: “It was an Olympic level of gymnastics that she was doing and singing completely perfectly… only Cynthia could pull that off. It was something just unprecedented.” — Simon Hayes [33:08]

---

Notable Quotes & Memorable Moments

• “I think that we made the right decision because when Ari and Cynthia started singing together… it was like their vocals meshed. Something very, very magical happens.” — Simon Hayes [14:32]

• “What I realized when I started in the film business is that sound is performance, and I love performance.” — Simon Hayes [33:27]

• “I thrive on being able to say to my directors and my actors, I got it. It sounds great. That’s the best feeling in the world for me.” — Simon Hayes [34:32]

---

Important Timestamps

• 03:24: Simon Hayes explains traditional playback/lip syncing in movie musicals.
• 04:40: Hayes emphasizes goal of “no transition” between speech and singing in Wicked.
• 06:10: The consequences of poor on-set sound and reliance on ADR.
• 09:05: Decision to record dialogue as intimately as vocals for seamless transitions.
• 11:17: Discussing the use of visible lavs and their digital removal for best audio quality.
• 12:24: Use of multiple boom mics for lead actors, even during close duets.
• 14:32: Impact of preserving live duet energy between leads.
• 21:33: Blending raw live ensemble with Broadway-quality overdubs.
• 22:52: Introduction and explanation of “thumper track” for choreography.
• 25:10: Custom color-matched in-ear monitors for on-set musicianship and VFX.
• 26:37: Technique for live tempo flexibility using keyboard in IEMs.
• 29:33: The “Defying Gravity” challenge: singing while airborne.
• 30:48: Silent wind technique explained.
• 32:40: Cynthia Erivo’s insistence on singing live during flight sequences.
• 33:08: Simon effuses about the magic of Cynthia’s performance.

---

Episode Tone and Flow

• The tone is technical but deeply passionate, celebrating both audio craft and musical performance. Simon Hayes clearly reveres the artistry and emotional truth of the actors, while Dallas Taylor’s narration is engaging, curious, and explanatory—perfect for both newcomers to sound production and musical aficionados.

---

For Listeners New to the Episode

This episode reveals the hidden artistry and technical wizardry behind Wicked’s celebrated “live singing” soundtrack. With behind-the-scenes anecdotes and fascinating breakdowns of both tech and teamwork, it challenges assumptions about what’s possible in Hollywood musicals—and leaves you listening for the real sound, every time.

---

Transcript

[Dallas Taylor]

Fall always feels like a reset. Vacations end, kids go back to school and the days get shorter and busier. During a hectic work week, finding time to cook a nice meal can feel almost impossible. That's why I love Factor. They have a huge range of chef prepared delicious meals that are ready in minutes no matter what your dietary needs are. Factor has you covered with options like vegan and veggie, calorie, smart, high protein and more. Eat [e-mail] TTH50 and use code TTH50OFF to get 50% off your first box plus free breakfast for one year. That's code [e-mail] for 50% off your first box plus FREE breakfast for a year. There's also a link in the show notes get delicious ready to eat meals delivered with Factor. This offer is only valid for new Factor customers with a code and a qualifying auto renewing subscription purchase. The holidays are approaching fast and it's time to get those gifts in order. With Sonos, you can give someone the gift of audio bliss without having to face the Black Friday crowds. That's because Sonos has a Black Friday sale running from November 20th through December 1st. During that time you can get up to 30% off their incredible speakers and soundbars, whether it's a portable Sonos Move 2, a set of Aero One Hundreds or a Sub mini for rich, powerful bass. To learn more, head to Sonos. That's s o n o s.com you're listening to 20,000HZ. The stories behind the world's most iconic and fascinating sounds. I'm Dallas Taylor. When I saw the movie Wicked, I was pretty blown away. For anyone who's not familiar, the film was adapted from a Broadway meet musical about the witches from the wizard of Oz. It was directed by John Chu and stars Ariana Grande as the Good Witch Galinda and Cynthia Erivo as the so called Wicked witch Elphaba. Between the performances, the score, the choreography and the production design, Wicked is an absolute spectacle. But the thing that impressed me the most was how great the singing sounded, especially because I had heard that all of the lead vocals were recorded live on set. This is virtually unheard of for many reasons. In movie musicals you've got dozens of people dancing, cameras and equipment moving around, all of which make a lot of noise. The singers themselves are dancing and interacting with the set and props, which isn't a recipe for a flawless vocal performance. The boom microphones that hang down from above have to stay out of the shot so they can't be too close to the action. And lavalier mics on the actors costumes can easily get jostled with all of that movement. Basically, it's an audio nightmare. For these reasons, the stars of movie musicals usually record their songs in advance and then lip sync to those recordings while filming.

[Simon Hayes]

On Old School Musicals, they weren't singing live, they were miming to a playback track.

[Dallas Taylor]

That's Simon Hayes, the production sound mixer of Wicked.

[Simon Hayes]

And the playback track would generally have been recorded with a studio microphone.

[Dallas Taylor]

Really, really close, as in close to the actors mouths to get the cleanest possible recording.

[Simon Hayes]

And the film microphone on the set potentially would have been much further away.

[Dallas Taylor]

This means that viewers can often hear the change in vocal tone when the actors go from talking to singing.

[Simon Hayes]

You hear this shift in the vocal and you go, whoa, here's the lip sync.

[Cast Member (e.g., Ariana Grande or Cynthia Erivo)]

It's not a place you can get to by a boat or a train. It's far, far away. Behind the moon, beyond the rain, somewhere over the rainbow, way up high.

[Simon Hayes]

And although we love those movies and we respect them, we all knew that people were lip syncing.

[Dallas Taylor]

As the production sound mixer, Simon is in charge of capturing any on set vocals, whether it's talking or singing.

[Simon Hayes]

Now, what I wanted to do in Wicked was we don't want to hear this transition between singing and dialogue because there isn't a transition because it's all live on the set.

[Cast Member (e.g., Ariana Grande or Cynthia Erivo)]

Alfie, now that we're friends, I've decided to make you my new project. Oh, you really don't have to do that. I know. That's what makes me so nice. Whenever I see someone less fortunate than I. And let's face it, right, who isn't less fortunate than I?

[Dallas Taylor]

On set, Simon has a lightweight all terrain cart loaded with equipment.

[Simon Hayes]

It's small enough that one person can roll it across the floor and it's light enough that two people can carry it up some stairs.

[Dallas Taylor]

On the bottom of the cart there are radio receivers which get the signals from all of the microphones in use. On top there's a 32 track mixing board plus three small screens that show what the cameras are shooting as they film. Simon records the onset audio known as the production sound.

[Simon Hayes]

And I'm going to be recording those isolated mic tracks so that I can present them to soundpost. But also doing my own mix for the picture editor in the way that I would like to hear it based on my what I'm seeing on my screens, as if I'm sitting in a cinema and I'm one of the audience.

[Dallas Taylor]

Members throughout the shoot. Simon works with the director, the actors, and the audio assistants or A2s to make sure the dialogue sounds great.

[Simon Hayes]

It's my job to record the cleanest vocals possible so that those original performances that the actors give us on the movie set make their way all the way through the editing process, all the way through the sound editing process and into the movie theater. Now, if I have a bad day at work or if I'm presented with challenges which destroy my soundtracks, then the actors will have to come in, they'll have to re record their vocals.

[Dallas Taylor]

This is called ADR or Automated Dialogue Replacement.

[Simon Hayes]

And potentially those performances aren't going to be quite as authentic as the ones recorded on the day.

[Dallas Taylor]

Now, almost everything we watch has some ADR in it. And if it's done well, you won't ever notice. But from an acting perspective, it's really not ideal.

[Simon Hayes]

We never get the actors back in together to ADR their piece. You know, an actor could be on a different movie in a different city, and we'll get them into a vocal booth and they will re record their dialogue on their own. So they won't be wearing their costume, they won't have the actor that they're communicating with sitting opposite them. They won't have the props in their hand that they were playing with. And so there will almost be a disconnect for the actor. And obviously really great actors can do it. But I think the more lines of dialogue that are ADR'd, the less likely the audience are to buy those performances. Someone that doesn't understand filmmaking may not think to themselves, this has been adr. The vocals have been recorded later, but they may just be living, looking at the actors, facial expressions, listening to the tonality of their voice and thinking, I don't trust this.

[Dallas Taylor]

But making ADR believable isn't just about performance. It's also about the natural reverberation of the space.

[Simon Hayes]

If we've got someone walking across a desert speaking, and we can just detect something within their voice that tells us that they were in a room, is that gonna make us think, do we buy it? And so these are the problems with ADR.

[Dallas Taylor]

In the real world. You can almost always hear the space around someone's voice. And to capture this on set, filmmakers use boom mics, which they can hold closer or farther from the actors, depending on the shot.

[Simon Hayes]

We want the sound to match the picture. The wide shot should sound slightly wider than a close up. A mid shot should sound mid because that's the way as human beings, we.

[Dallas Taylor]

Expect sound to be, but with a musical it's different.

[Simon Hayes]

Basically, when someone's singing, there is only one type of sound that I want and that is close sound. In the same way that when we hear someone singing on a pop record, their voice would be mic'd.

[Dallas Taylor]

And to keep the vocal tone consistent, Simon recorded the dialogue with that same intimate closeness.

[Simon Hayes]

What I didn't want to do with Wicked was put any space around the dialogue because I knew that we were generally going to be going right into singing. I wanted that close up dialogue dialogue so that there was no transition into the singing voice.

[Dallas Taylor]

The trouble with schools is they always try to teach the wrong lesson. Plus, when a voice is mic'd from far away, you get less of the pure vocal sound and more noise. Now, when there's not much music to compete with it, that can sound nice and realistic, but if the music swells, you'll have to turn the dialogue up to match it and all of that noise you recorded comes up with it. So close mic'd dialogue gives you more flexibility to boost vocals cleanly, even when the score is loud, because it's a musical.

[Simon Hayes]

I knew that even when the actors weren't singing, we would always be preparing for the next song and the score would be building. So again, I wanted as much signal to noise as possible, which is closely mic dialogue. So that if John Chu said to Andy Nelson and John Marquez, our fantastic re recording mixers, I'd like to hear more score. Can we push the score? They'd be able to say, no problem.

[Dallas Taylor]

To make that close mic'd sound possible, they relied heavily on wireless lavalier mics. Typically these are hidden in the actor's costumes, which is a whole mysterious art in and of itself.

[Simon Hayes]

It is a black art. It's an absolutely creative skill and we just have a whole host of tricks. We've got all sorts of mounts, we've got ways of keeping the microphone so that it doesn't get rubbed by the costume. You know, we put little bits of wire on a mount to push the costume out, but not enough so that you see a bulge. A good lav mic sounds great. A bad lav mic is adr.

[Dallas Taylor]

But with some costumes you just can't get a good sound from underneath the clothing.

[Simon Hayes]

If it's a bit of velvet, a bit of chiffon, a bit of silk, it's either going to be rustling or it's going to sound muffled.

[Dallas Taylor]

And the elaborate costumes of Wicked included lots of those materials.

[Simon Hayes]

Ariana Grande, Gelinda, all of her Costumes were very, very ruffly. They were beautifully designed. But it wasn't going to be possible to mic her without putting the mics on the outside. And so what we did on Wicked was whenever we didn't have a great lav placement that we could hide, we just put the microphone straight on the outside and it was removed in post.

[Dallas Taylor]

Meaning the visual effects team would digitally paint out the microphone. It was an extra step that Simon and the team felt was well worth it.

[Simon Hayes]

Removing a lav mic with VFX in post has a financial penalty, but so does adr. But only one of the two supports the original performance, and that is removing it with VFX in post.

[Dallas Taylor]

Now, even though they relied heavily on lavalier mics, boom mics were still an important part of the equation.

[Simon Hayes]

We always had two booms, and sometimes three.

[Dallas Taylor]

Anytime Ariana Grande and Cynthia Erivo were on screen together, they each had a dedicated boom mic above them.

[Simon Hayes]

Even if Ari and Cynthia are singing absolutely nose to nose, which they are many times in the movie, we always had two boom mics. Even if these two boom mics were like jostling for position and only missing each other by one inch, these booms.

[Dallas Taylor]

Would normally be just out of frame. But in a pinch, they could paint them out digitally like they did with the lav mics.

[Simon Hayes]

I think maybe five times throughout the whole movie, we painted booms out.

[Dallas Taylor]

Recording all of these audio tracks is a ton of work, but it gives them more options when it comes time to mix the film.

[Simon Hayes]

Because I'm presenting these multi tracks, I'm not making absolute final decisions for the director on the movie set. I'm presenting him with choices that he can make a decision on based on how his sound effects are going to sit around the vocal, how the score is going to sit around the vocal, and how he wants the final film to sound. So really what I'm trying to do is be an absolutely expert track layer and present choices.

[Dallas Taylor]

Now, whenever there's a duet and the actors are singing right into each other's faces, those mics are inevitably going to pick up both voices, which is not ideal for mixing.

[Simon Hayes]

My instinct as a production sound mixer is to get the cleanest vocals. And so on Ari's close up, I would love to ask Cynthia not to sing. And then on Cynthia's closeup, I'd love to ask Ari not to sing. But what I decided very, very early on was that if I asked one of them to mime, it wouldn't do the emotions justice, because the way that they were Singing at each other had so much umbrage when they're hating on each other.

[Cast Member (e.g., Ariana Grande or Cynthia Erivo)]

I hope you're happy, right?

[Simon Hayes]

Or so much love developing as their friendship's blossoming.

[Cast Member (e.g., Ariana Grande or Cynthia Erivo)]

I think we found a place where we belong. I wanna be in this hoi belong.

[Simon Hayes]

That I felt that I would be taking something away. So here's the thing. I didn't even ask. I just went, you know what, guys? You can sing over each other as much as you want to. We will work it out as best we can in post production. And I think that we made the right decision because when Ari and Cynthia started singing together, every single time, it was like their vocals meshed. Something very, very magical happens when those two start dueting together. And I could feel the hairs on the back of my neck starting to stand up. And many times, many, many times, I had tears rolling down my cheeks. And you just become. It's almost like my sound recording equipment is like a musical instrument, and I'm just feeling the faders and I'm playing and I'm feeling their dynamic range, and I just become part of this. We call it the dance, and it's the filmmaking dance, and it's a dance that all of us do. The boom operators are dancing with the grips, the grips are dancing with the camera operators. They're all dancing with the actors. And we're just all creating this piece of cinema together. And that was kind of like every day on Wicked.

[Dallas Taylor]

Recording the stars of Wicked was a complex process, but capturing the chorus required a completely different approach. And the biggest challenge was yet to come.

[Simon Hayes]

Throughout the whole filmmaking process, all of these people would say to me, but what are you going to do about defying gravity? Cynthia's flying through the air. Surely she's going to lip sync to that. Surely you won't be able to record that live.

[Dallas Taylor]

That's coming up after the break. AI is in the news a lot these days. We're all trying to make sense of how it'll change our lives, our relationships, and, of course, the way we work. And that's where the Working Smarter podcast comes in. In each episode, the hosts talk to real people who are actually using these tools about what it really looks like to work with AI. For instance, there's a chef who uses AI to make prep work less of a grind. That way he can be more creative in the kitchen. Then there are scientists who are using AI to find long lost shipwrecks in the Great Lakes. And there's an episode about how AI is being used in the world of sports science, including wearable technology and algorithms trained on video footage from practices. With the right experts guiding them, tools like these can help us prevent injuries and better understand the human body. Working Smarter goes beyond the headlines and shows how AI can help you do more of what you do best so that you can work smarter too. Follow Working Smarter wherever you get your podcasts or visit Workingsmarter A.I. congratulations to James Allenspock for getting last episode's mystery sound right. That's the Whammy sound effect from the game show Press yous Luck. When a player lands on a whammy space, this sound plays and they lose all the money they've earned so far. Then they play a short animation featuring the mischievous Whammy character who's kind of a red devil with a cape. Here's one where the whammy skateboards into a tree, stop and I'll whammy. And here's this episode's mystery sound. If you know that sound, tell us at the web address mystery.2000. Anyone who guesses it right will be entered to win a super soft 20,000Hz t shirt. If you're dreaming about launching a business, it's probably because you have a great idea. But of course a successful business needs more than just brilliant ideas. You need a professional website, a way to collect payments and manage inventory, marketing strategies. And the list goes on. That's where Shopify comes in. Shopify powers millions of businesses around the world, including 10% of all E commerce in the US. With Shopify, you can easily make a polished web store with hundreds of ready to go templates. If you need copy, Shopify's AI tools can help you write product descriptions and headlines, and even enhance your product photos. You can run email and social media campaigns right from Shopify and manage inventory, international shipping and returns in one place. Turn those dreams into and give them the best shot at success with Shopify. Sign up for your $1 per month trial and start selling today at shopify.com 20k. That's shopify.com 20k shopify.com 20k. When I was younger, I used to fantasize about having the perfect sound system in my house. Something where pristine sounding music could follow me through every room of my home with almost zero effort by me. And with Sonos, I've finally made that dream a reality. Sonos makes speakers and soundbars that sound fantastic and sync together into one interconnected system. That means I can stream a live concert in the family room, then step into the kitchen and keep Listening in there. If I go outside, I can take the music with me using the portable Sonos Move 2. And if I want to change anything, I can easily make adjustments through the Sonos app. With Sonos, the options really are endless. If you've been thinking about trying out a device from Sonos, now is the perfect time. Their Black Friday sale runs from Thursday, November 20 through Monday, December 1. For those 11 days, you can get up to 30% off their incredible speakers, soundbars and more. So don't miss out. Head to sonos.com now that's s o n o s dot com. During the production of Wicked, the vocal performances of all the lead actors were recorded live on set. It was a risky move that came with all kinds of technical hurdles, but recording the chorus members posed a different set of problems.

[Simon Hayes]

In choruses, there could be a lot of choreography, footfall, there could be some people who are better dancers than singers who are singing along in. And so basically what we did was we said, look, we're going to record them live wherever we can, but we're not absolutely committing that these are going to be the vocals that we use in the movie. We're going to support those live on set vocals with re recordings of fantastic ensemble singers.

[Dallas Taylor]

For instance, there's a song called no One Mourns the Wicked where the villagers of Oz celebrate the Wicked Witch's death. And when they filmed that scene, there.

[Simon Hayes]

Were people singing that were almost chanting because they weren't professional singers, they were professional dancers. And so there was this very, very raw and real part of the way that they were performing that sounded like they were angry villagers.

[Dallas Taylor]

Then in post production, these on set vocals were blended with studio recordings of singers from the Broadway production of Wicked. Here's the official Broadway recording from 2003.

[Cast Member (e.g., Ariana Grande or Cynthia Erivo)]

No one wants to.

[Simon Hayes]

John Chu and the music team assembled some of the best singers from the Wicked stage show and got them to come back in and basically become part of the ensemble vocals in the movie.

[Dallas Taylor]

Here's that same section from the movie.

[Cast Member (e.g., Ariana Grande or Cynthia Erivo)]

No one More so rare now at last it's dead and gone now it last destroyed throughout your life.

[Dallas Taylor]

But there was one more sonic ingredient to these recordings which involved something called a thumper track.

[Simon Hayes]

Basically, we would take the sub bass from Greg Wells backing track. We would remove anything above 40 hertz. I think our sweet spot was 38 hertz. And what the choreographer would do, Chris Scott, he would say to his team, right guys, we're gonna do this one just for sound. Don't verbalize anything, okay? We're just gonna do the dance.

[Dallas Taylor]

Then they'd cue up the thumper track for the chorus to dance to, which.

[Simon Hayes]

Basically goes W, w w, W. And Chris Scott would say, and 1 and 2 and let's go 3 and. And suddenly we would get them all doing their stamping desk, slamming completely in tempo to the track.

[Dallas Taylor]

The only music in that recording would be the thumper track. And since it's such a low frequency, it could be removed completely with audio software, giving them a clean recording of all that onset movement.

[Simon Hayes]

And so if you like, we had the best case scenario. We had the live solo vocals, which contain emotion. We had re recorded and perfectly sung ensemble vocals. But then we had the real sound of the foot stamps and the desks being smashed from the set in the right acoustic. They weren't rebuilt sound effects. And when you blend it all together, you've got something that sounds very, very real.

[Cast Member (e.g., Ariana Grande or Cynthia Erivo)]

Dancing through life.

[Simon Hayes]

Cause dust is what.

[Cast Member (e.g., Ariana Grande or Cynthia Erivo)]

We come to Nothing matters But knowing nothing matters.

[Simon Hayes]

And I think that that's what made it such a unique soundtrack.

[Dallas Taylor]

Of course, in order to sing on key and dance in time, the actors need to hear the music. But if they just blast the music through loudspeakers, that sound would get picked up by all the booms and lav mics. So instead the cast wore in ear monitors or IEMs, which are basically fancy earbuds designed for live performances like concerts. And this was another thing to hide from the cameras.

[Simon Hayes]

And so what we did, we got the cables and the IEMs themselves to be manufactured to match the skin tone of the actor. So for Cynthia, we liaised with the makeup designer who had designed the color of Elphaba's green skin. And we basically got that exact color match for her IEMs.

[Dallas Taylor]

And for Ariana Grande, they matched her in ear monitor to her primary makeup tone. This color matching meant that on the wide shots, the IEMs were far away enough that you couldn't even see them. But on the mid shots and the close ups, they had to be painted out.

[Simon Hayes]

And so that was again VFX supporting original performances and giving revenue and Cynthia full acoustic support in the same way that they would have support if they were on stage doing a live concert.

[Dallas Taylor]

As for what was playing in those IEMs, it was the core rock instruments of the score, which were recorded by music producer Greg Wells. Basically everything but the orchestral layers.

[Simon Hayes]

Greg's tracks that we played back were pretty much final mixed and all they had to do is have orchestration added to them.

[Dallas Taylor]

But singing to pre recorded music doesn't allow for any variation in the tempo, which is one way for a singer to add some personality to a song, if possible.

[Simon Hayes]

What we wanted to do was to play a keyboard into their IEMs and actually allow their performance and their emotions to drive the tempo of their singing. If they wanted to take a moment to reflect in the middle of a song, they could do if we had a keyboard player accompanying them but not leading them. So what we did, wherever possible, was we allowed the actors to go off tempo with a keyboard, but still knowing that at a certain point the drums and the bass was going to come in. And suddenly we have this rhythm in this tempo. That's the lifeblood of Wicked. And at that point, we would do a quick crossfade across in their IEMs from Live Keyboard into Greg Wells backing track. For instance, Cynthia singing I'm not that Girl. Her first verse and a half was completely freeform. The orchestration is incredibly sparse. Sudden silence, and you can hear her breaths and you can just feel her emotions.

[Cast Member (e.g., Ariana Grande or Cynthia Erivo)]

Hearts need in a giddy world.

[Simon Hayes]

And that was because we gave her that freedom which she asked for, which was the accompaniment from the keyboard. But then as the rhythm comes in and we do the fight across and then we're into the big number.

[Cast Member (e.g., Ariana Grande or Cynthia Erivo)]

Don't dream too far don't lose sight of who you are.

[Dallas Taylor]

Of course, the crew had to hear the music too, in order to time all of their camera movements and boom movements and lighting changes. So while they shot, nearly everyone wore headphones.

[Simon Hayes]

And what they would hear in their headphones was Ari Cynthia's or Johnny Bailey's, Jeff Goldblum's or Michelle Yeoh's voice blended with the final music track in the way that I felt they should be blended. But if they take their headphones off, they've got those actors singing completely acapella.

[Cast Member (e.g., Ariana Grande or Cynthia Erivo)]

You're so strong. Though I do admit it came on fast, still, I do believe that it can last.

[Simon Hayes]

So it was a very, very unique experience.

[Dallas Taylor]

But the most unique experience that Simon had on Wicked was when they filmed the song Defying Gravity. It happens in the climax of the film when Elphaba learns to fly on a broomstick and gets chased through the sky by an army of flying monkeys. That meant that Cynthia Erivo would be strapped into wires, doing all kinds of flips and zooming through the air, all while singing.

[Simon Hayes]

And throughout the whole filmmaking process, all of these people would say to me, yeah, but what are you going to do about Defying Gravity? Cynthia's flying through the air. Surely she's Going to lip sync to that. Surely you won't be able to record that live. And I kept on saying to everyone on the crew, listen, of course we've got the pre record in our back pocket just in case. It's a impossible for her to sing live. But you've seen the way that Cynthia is performing everything live. She's gonna wanna go live. We've got to be ready, guys.

[Dallas Taylor]

The first thing that they had to figure out was how to make it look windy without the noise.

[Simon Hayes]

Of course, Cynthia needed to look like she was flying at high speed through the air. But wind is the enemy of production sound. Normally, when we need wind, it's manufactured by big, big rotor blades with either if we're on exteriors, big V8 engines, or if we're on interiors, very, very loud electric engines. And you've just got this mechanical noise. And it will generally mean that you're going to have to ADR everything.

[Dallas Taylor]

To avoid this, they used something that Simon and various special effects designers have been refining for years called Silent wind.

[Simon Hayes]

What Silent wind basically is, is our special effects supervisor had all of his wind making machines outside the sound studio. And then he ducted the actual wind itself in through flexible plastic pipes. And he had his special effects team holding one pipe each, and they would be pointing them at Cynthia. And these jets of wind would hit Cynthia wherever she was flying. But because the machinery was outside the soundstage, I couldn't hear the machinery. All I could hear was a kind of broadband sh, which of course, can be removed from the vocal pretty easily these days.

[Dallas Taylor]

But the wind motors weren't the only things on set that had to be quieted down. For instance, the stunt wires that Cynthia was rigged up with were powered by noisy hydraulic machines. So they moved those outside the soundstage as well. At one point, they had laid a track for a crane to move a camera around.

[Simon Hayes]

And on the rehearsal, it's going crick, crack, crick, crack. And it was noisy. And I said, guys, I'm sorry, we gotta take that crane off that track and we've gotta relay it and put carpet underneath it. And so, basically, as a film crew, we just all pulled out every single stop to make what would normally be an actual sequence in a superhero movie. That's what defying gravity is. It's like a superhero movie, but with someone singing live. And normally that set would just be unusable for sound. And we made it quiet. And when we got Cynthia in that rig and John Chu said to her, just matter of fact, hey, Cynthia, how are you feeling? Do you want to go live? Cynthia was just like, of course I'm singing live. And we just kind of all looked at each other and there was this knowing kind of glance around the room where all of us who had worked so hard to get this set quiet went, thank goodness we made the effort.

[Dallas Taylor]

And so Simon and the crew watched as Cynthia was slingshotted through the air, flipping and spinning while delivering a spot on vocal performance.

[Cast Member (e.g., Ariana Grande or Cynthia Erivo)]

Gravity. And so not much. No memory now.

[Simon Hayes]

It was an Olympic level of gymnastics that she was doing and singing completely perfectly as she was doing it. I think only Cynthia could pull that off. It was something just unprecedented.

[Dallas Taylor]

For Simon. Capturing a performance like that is what he lives for.

[Simon Hayes]

What I realized when I started in the film business is that sound is performance, and I love performance. And when an actor is absolutely nailing their character and I can feel it and I know that I'm recording it beautifully, that's what I feel I was born to do. And so there is kind of this feeling when I'm sitting on that movie set. Although I am absolutely immersed in this wonderful feeling of creativity, there's also a feeling that I'm on a knife edge. I've got to make sure that I'm perfect. I may not get another take like that. I can't say, hey, you know what, can we go again? If that was the perfect take for performance, that was the take that the director loved. And I love that feeling. I live for that feeling. I really, really, really thrive on that pressure. And I thrive on being able to say to my directors and my actors, I got it. It sounds great. That's the best feeling in the world for me.

[Dallas Taylor]

20,000 Hz is produced by my sound agency, Defacto Sound. To hear more, follow Defacto Sound on instagram or visit defactosound.com this episode was written and produced by Casey Emerling and Andrew Anderson with help from Grace East. It was sound designed and mixed by Joel Boyder. Thanks to our guest, Simon Hayes. To learn more about his work, visit SimonHayes.com finally, subscribe to my YouTube channel, Dallas Taylor MP3 for video exclusives over there you can see my behind the scenes trips to Cirque du Soleil, snl, Disney Imagineering and more. You can also find clips of these stories on Instagram and TikTok under that same name. Dallas Taylor MP3 thanks for listening.

[Kirk Hamilton]

Hey there. I'm Kirk Hamilton and I want to tell you about my music podcast, Strong Songs. I know we've never met, but I think you might like it. I've made more than 100 episodes on songs by Aretha Franklin, Bruce Springsteen, Peter Gabriel, Soundgarden, and so many more. Breaking down and reassembling each song to help you hear things you never heard before. Let me show you. We start with something lush and complex, then maybe take it down to just the synthesizers. All right, let's see what the guitars are up to. Okay, how about the horns? The horns sound good, so let's put it all back together and see where it takes us. That's the gist. A feel good show about the joy and craft of music. So if you like songs, I have a feeling you might love strong songs. Find it wherever you get your podcasts.