Minutes before I’m supposed to meet mix engineer Leslie Brathwaite for the first time, he texts me to reschedule. “So sorry, had to come make some tweaks on a Pharrell mix upstairs in my room!” the message says. I let it slide.

Leslie Brathwaite is a name you might not know, but he is integral to bringing music to life. One of his latest accomplishments is mixing Cardi B’s Invasion of Privacy, which recently won Best Rap Album at the 61st Grammy Awards, making her the first female rapper to win the category as a solo artist.

As the mix engineer for Invasion of Privacy, it was Brathwaite’s job to take all of the recorded material for the project — from vocals to instruments to individual sample hits — and craft the nuanced balance and relationship between every element before the music heads off to be mastered and then released to the world. In the past, he’s done the same for T-Pain, Rick Ross, Travis Porter, Gucci Mane, Beyoncé and Jay Z, Future, and Lil Uzi Vert (to name a few).

After last Sunday’s Grammy Awards, Brathwaite now has seven Grammy nominations under his belt. In the post-Grammys glow, he talks with The Verge about what a mix engineer does, what it was like to work with Cardi B on Invasion of Privacy, and he shares some of his favorite studio tips, tricks, and plug-ins.

This interview has been lightly edited for clarity.

What exactly does a mix engineer do, and why is your job necessary for a song or album?

Once the artist and the musicians and the producers and everyone gets together and records all the material, I have to sift through everything and make decisions like which vocal take is the best? How loud is the vocal going to be? How loud is the kick drum going to be? Is the bass going to be a little thicker or thinner?

I’m the one that balances out the levels. I’m the one that chooses the best takes. I’m the one that decides if the bass is going to be in in this section or out in another section. If an instrument needs tuning or if somebody can’t sing that well, I can help fix that up a little. It’s necessary because the song and the music won’t sound as polished otherwise. A lot of times, the song in its raw form can’t really communicate what it’s trying to communicate unless things are put in the right context.

“They were like, ‘Dude, we got to make this Cardi B album in a week.’ I went to Miami, and we mixed the entire album in a week and a half.”

Do artists normally come to the table with an idea of what they want it to sound like, or do you get creative liberties?

There’s a 50 / 50 there. The more inexperienced artists let me do my thing. They’re coming to me knowing that I have so much knowledge. They want my input, and they want to know what I think. And it’s like that with the more established artists, too, but they tend to have more guidelines with what they think will work for the mix. Even the people with the most ideas still leave room for me to do my craft and insert my ideas, though, because they value perspective.

How did you start working with Cardi B?

Craig Kallman, the head of Atlantic Records, called me in 2017, and said, “Hey man, we signed Cardi B, and we want you to mix her album. I think you’d be perfect for her and her temperament.” I didn’t hear from him for a while, and then I got a call in March 2018. They were like, “Dude, we got to make this Cardi B album in a week. She’s pregnant, and we got to shoot all these videos. Can you make it to Miami? She really wants you to mix it down there because she wants to be a part of the process.” I was like, “Hell yeah!” I went to Miami, and we mixed the entire album in a week and a half.

Earlier, you told me you like your job because you don’t have to interact with artists.

Let me clarify. I do like humans. In general, the thing is, I like music, but I’m not a particular fan of the music industry. And so I like that buffer between me and all the BS. A lot of the time in the music industry, you find a lot of wannabes, people who think they know everything, and artists who are just crazy. That’s the kind of stuff I tend to avoid.

Fortunately, in my career, I’ve dealt with a lot of wonderful people. Every now and then, it is fun to work with the artist and have them right there as we’re working. Cardi was in the next room doing a lot of promo stuff, and she would come and peek her head in to listen to the mix and make little comments. But she gave me space to work and do my thing. It’s her first major album, and I think she was curious about the process. I’m always happy to be a part of that. Like when I mixed Beyoncé and Jay Z, she flew me to London and was there. It’s Beyoncé. Of course she can be there every second of the day if she wants to! But it’s not my norm.

Any particularly good stories from your time in Miami with Cardi B?

Yes, but I can’t share anything! [Laughs] I will say she is so much fun to be around. I mean, she is a party on wheels. What you see is what you get with Cardi. She is so authentic and so real, she couldn’t fake that if she wanted to. There’s never a dull moment with her.

I also like that she’s very nice. Every night, she would walk around and make sure she spoke to every single person in the studio from the front desk girl to the studio manager. She didn’t care how tired she was. One late night, she was walking out, stopped, and then walked back to thank the interns and the runner. She’s just so sweet. You can’t teach that, and you can’t buy that.

After working with her that week and a half, I said to myself, “Man we got something special here.” This is one of the better albums I’ve mixed in a long time. It’s a really solid album.

Do you have a favorite song on Invasion of Privacy in terms of the way you mixed it?

Yeah, the first song, “Get Up 10,” and “Ring,” with Kehlani. Those are my two favorite mixes, and they were coincidentally the first two records I mixed on the album.

Why are they your favorites?

“Get Up 10” just had a certain energy to it. I thought it was a perfect intro album song with the come-up story in there. I love the way it grows for a while with just pianos and strings, and then when the beat drops halfway through the song, the energy is amazing. And then I just like “Ring” because Kehlani combined with that record sounds so good.

What was your path to becoming a mix engineer?

I was born in Saint Thomas in the Virgin Islands. It’s a very musical culture, centered around calypso and soca and reggae. From a very early age, I would follow the calypso bands and ask them if I could hook up the amplifiers or try to help them wrap cables. I was always intrigued with how things sounded. As I got a little older, I would sit for hours and play records from my dad’s collection, listening to the kicks and the snares and the bass in songs. I would read the credits and was really interested with all these titles and the positions of people that made the stuff work. One day, my guidance counselor gave me a little pamphlet from Full Sail. When I took the tour with my dad, I was like, “This is where I want to be.” I felt like I was home, seeing all the buttons and the boards and the speakers.

After I graduated, I was a runner at D.A.R.P. Studios in the ‘90s. I’d get coffee, go for McDonald’s, clean the bathrooms, whatever I could to stay around the studio. I was an unpaid intern, but I had full access to the studio. That was my exchange. I did anything they asked, but I also had the keys to everything. I worked my way up within the studio. I went from being an intern to an assistant engineer and then from an assistant engineer to a recording engineer. Before I knew it, I was mixing. My very first big mix was Monica’s “Don’t Take It Personal.” After that, I decided if I wanted to be a full-time mixer, I had to stop recording. I just had to be a mixer.

Why?

The trend in the industry was that people wanted specialized things. If you’re going into a hospital, and you know you have to have a brain tumor removed, you don’t want a general surgeon to do it. You want a brain surgeon. I saw that mentality in the ‘90s. People would much prefer a mixer to mix their records than a guy who recorded and mixed, and mixing really spoke to me because it’s just about me and the music.

Do you have a signature sound when you mix?

I think so. I’m known for being able to deliver real solid low end without it sounding muddy. It’s a consistency in bringing the low end forward but still having it all sound clean and crisp.

“When the technology uses us, that’s when it gets bad.”

What plug-ins are your favorites to help achieve that?

If I had to narrow it down to one plug-in, I would choose Little Labs Voice Of God. It’s a plug-in for low-end shaping, and it’s amazing on basses, kicks, and 808s.

What is the balance between how much tech can add to a mix versus what someone inherently brings to the table as an artist?

Technology, in general, is good when it’s used as a tool. When we use the technology, that’s great. When the technology uses us, that’s when it gets bad. And what I mean by that is when people depend too much on plug-ins and are always waiting for the new software pack to come out. Understanding the craft is what’s important. Craft is what’s going to win out. Plug-ins come and go. The technology changes. I learned on tape machines and large-format consoles, and now I’m essentially just on a computer.

It’s amazing how it’s all shrunk, and you can now work from anywhere.

Exactly! When we were trying to hook up at the National Association of Music Merchants show, I had my laptop with me and was mixing a Pharrell song for the upcoming Pokémon movie soundtrack in my hotel room. I get so much more done now. One of the biggest advantages in this shift is that something that would legit take me two hours to do on a tape machine and reels now takes me less than two seconds to do with a copy-paste function. There’s just no compromise on the efficiency, and we can work at such an alarming rate as opposed to how we used to work.

How do you decide where to begin with a mix?

I usually begin with vocals. I feel like vocals are the most important part of the song. I take what’s called a subtractive approach. I remove mistakes or strong S’s. When people pronounce certain words, the S’s tend to be a little poignant on microphones. If somebody’s wearing bracelets or chewing gum or something, and you can hear those sounds in the dead spaces, I edit all that stuff out. It’s a lot of tedious cleanup work that some engineers don’t do.

“I just turn the knobs until it sounds good. And that’s my honest-to-god approach.”

Once I get the vocals sounding to where I love, then I go to the drums. The relationship between the kick drum and the bass is very important, especially for any type of music that’s hip-hop based. Even a lot of pop like Ariana Grande or Beyoncé has a hip-hop drift, so the kicks and the 808s and the bass all have to work really well together. From there I work my way down the instruments and then once I get all the music sounding a certain way, I bring the vocals back in and marry them together.

When you’re deciding if something is perfect and you’re going to move on, are you relying on technical tools like spectrum analyzers or a gut instinct?

It’s just something in my head. I always tell people music is about how it makes you feel, period. Rely on your feelings; rely on your gut. I close my eyes a lot when I listen. I don’t like to look at the dials and the plug-ins and the meters. People will ask me technical questions like, “Well, what frequency did you roll off?” and I’m like, I have no idea. I just turn the knobs until it sounds good. And that’s my honest-to-god approach. There are times when I pull up a plug-in and just start turning knobs. Then, when it sounds right, I’ll just stop and I don’t even know what the hell number I landed on. I’m not interested in technical readouts. It’s all about feel. But it’s important, in my opinion, to understand the technology and algorithms and everything else you’re using. I understand it and can have the most nerdiest, technical conversations on the planet. However, my process and the way I’m driven is mostly about feel.

Some people don’t know how to get out of either side. Some people are stuck all the way in the technical, and then some people are stuck all the way in the feels and the vibes. And I think it’s important to understand both. Make sure you are using the stuff, and that the stuff isn’t using you.

You become so practiced in the technical part that your brain can parcel it away.

Yep. Actually, last night, I was mixing some records, and I had to do some clean versions. I can go through and clean them up without having to scroll through the entire song. I know what the waveforms of certain curse words look like. It’s just from doing it so much. I have a 99 percent margin when it comes to being right when spotting curse words.

What’s the most common recording mistake you see when you get audio to mix?

Distortion. That’s probably the most common one, where people are yelling into microphones or into pre-amps or the recording engineer just didn’t understand what type of level needed to be set for the incoming audio. And distortion is a very hard thing to fix because once it’s there, it’s there. It’s the most common problem, and it’s equally the most frustrating thing to fix.

What are your thoughts on the rise of bedroom producers and artists making songs from beginning to end themselves?

I love it. It’s funny because I remember when Pro Tools and everything else started becoming more user-friendly and home-based with laptops, and anybody could do it, so to speak. A lot of people asked if I was worried about my job since people can now mix stuff in their house. I actually think it’s job security because giving everybody the tools doesn’t give everybody the talent. And so it then really keys people into the fact that, yes, you can have the tools, but you have to have the tools and the talent.

“Giving everybody the tools doesn’t give everybody the talent.”

It’s good to make things accessible to kids because there are people who would have otherwise never gotten their hands on some sort of recording software and realized that that was a passion of theirs. One of the biggest tragedies in life is people not realizing what they’re talented at and not realizing what they’re passionate about. A lot of times, those two things can, and usually do, line up. So having the technology become increasingly available in every household on every laptop can enable more people to discover and invest in their talents.

Do you need less help now that you work on a laptop instead of with bigger equipment like a console?

Yeah. Back in the day, I needed an assistant. An assistant was the person who physically did everything like align the tape machines or make all your patches on the patch bay. When you’re finished mixing, an assistant will make a record of all the gear settings. There were times when we would actually take physical Polaroids of the gear and keep them in a folder. Or when things advanced a little bit and most of the consoles had recall systems, the assistant would be the one to save all the recall information or recall the mix when I needed to bring it back up. But now it’s all in the computer. A push of a button saves your session. A push of another button brings your session comes back up. There’s no need to calibrate a tape machine or patch anything. So the physical use of an assistant went away for me.

Do you have a home studio, or do you work out of a professional studio?

I work out of a facility here in Atlanta called ICON Studios. Akon and I own a section in the back part. We built out a two-person private facility just for us. He rents out his portion a lot, but my room pretty much stays unbooked because I’m always in here. I can’t do the private studio at home thing. That’s where I’m husband and daddy!

“The songs I spend the least amount of time on sound the best. That’s not a coincidence.”

After music leaves your hands, where does it go?

It goes directly from me to a mastering engineer. Mastering serves a couple of different functions. One is to make it as loud as possible for all mediums. Second, it’s to make everything on an album sound consistent. For instance, with the Beyoncé and Jay Z album, I mixed on there, Tony Maserati mixed on there, Young Guru mixed on there, and Beyoncé’s recording engineer mixed a song on there. So you’ve got four different mixers. All mixers are going to come in with slightly different levels and slightly different feels. So the mastering engineer’s primary function is to make sure all of those mixes and levels are similar so the album feels cohesive. I guess the best way to describe it to people in very layman’s terms is, you know when you’re watching TV and then the commercial comes on, and the commercial is like, dumb loud? That’s the effect that you don’t want to happen on an album.

So when you’re finished mixing a song, it’s much quieter than the final product? And maybe people would describe it as sounding flatter?

A little bit, yes. So mastering will bump it up a little bit volume-wise. They do have control over the basic EQ bands like lows, mids, and highs, but when it leaves my hands, the mix and the blend and the relationship between the vocals and the instruments, that’s what you’re hearing. You’re just hearing a more polished version of that once it leaves the mastering engineer.

Has there ever been a song where you worked on it for ages and you could not come to a mix you liked?

Sure. I could probably say that about most of the songs I mix. Even with a song that does well and people love the mix I can always find something to criticize. What I’ve noticed, and I think this has contributed to the way I mix, is that the songs I spend the least amount of time on sound the best. That’s not a coincidence. You can unravel a mix just as much as you mixed it. I know I’m done when I start asking too many questions and second-guessing my decisions. And so my process usually tends to be very quick. That’s also a part of my signature. It contributes to a better product because I don’t spend half my time trying to perfect things. One of my mentors, the great Bruce Swedien, said the same thing. And Bruce was Michael Jackson’s mix engineer.

“You don’t always have to get fancy and get into hot new plug-ins. Basic concepts can make things sound good.”

Well, what do you consider quick?

I’d say, on average, a rap song could take me three hours to mix. A song with singing and more pop vocals can take me about six to eight hours. That’s relatively quick in my world. Some engineers take a week to mix a song.

What!

[Laughs] Yeah! And that was the norm in the ‘90s. Back then, the average was three days to a week to mix one song, so even now when I tell people I can mix a rap song in three hours or a pop song in six hours, they look at me like I’m crazy. A lot of people still think that the standard is a few days.

What do Cardi B’s session files look like for Invasion of Privacy? Are they pretty clean and organized?

Hers are pretty organized. “I Like It” was probably the most complicated session because it had J Balvin and Bad Bunny and her. So it had all their vocals, and then the track itself was a replay of a sample. A lot of people think that’s the actual sample [from Pete Rodriguez’s “I Like It Like That”], but it was actually replayed. Craig hired people to replay every aspect of that sample, and it turned out to be like, 60 tracks worth of stuff! I had to use the replayed material, plus the new drums, plus Bad Bunny’s vocals, plus J Balvin’s vocals, plus Cardi’s vocals, so there was a lot going on in that particular session. Most of the other songs were pretty straightforward.

I assume they rerecorded for “I Like It” because of sample rights?

Yes, it’s because they didn’t want to clear the sample. The physical sample costs way more to clear than if you replay it. Then you only have to clear on the songwriting part, and not the performance.

Craig anticipated that that song was going to be big and it was going to get offers for sync rights and movies and so on. It just makes doing all that business a whole lot cleaner when it’s a replayed sample than to have to get the original cleared.

When you physically sample somebody else’s work, they are now a part owner of that song. And so anything that happens with that song, they have to also approve. That just makes it convoluted. So if they used the original sample, and the NFL came to them and said, “Hey, we want to use ‘I Like It’ as our promo for the Super Bowl,” now they have to go to all the songwriters or whoever owns the copyright to get things sorted. But if you replay it, you don’t have to. You just have to make sure there’s compensation and credit for their songwriting, but you don’t have to clear the actual use.

I’ve heard you are not a fan of using tons of plug-ins when you’re working.

Exactly.

So that assumes the audio that comes to you is already in good shape.

Yes. The thing is, at this point in my career, I am working with the Cardi Bs and the Pharrells and the Beyoncés. The standard level of music that they’re dealing with is usually top notch to begin with. Even in the case of stuff that I get from new artists like Lil Uzi Vert, sometimes the fix and the way to really make something sound good is to revert to primal mixing. Turning stuff up, turning stuff down, adding a little lower end, adding a little high end. You don’t always have to get fancy and get into hot new plug-ins. Basic concepts can make things sound good.

That being said, I know you have some favorite plug-ins.

Voice Of God is my go-to. I like the Fairchild 670 Tube Limiter by Universal Audio on my kicks and bass. I also like old-school type EQs, the Waves PuigTec EQs and Universal Audio Pultec EQs. I’m a huge Waves user. I use their Renaissance line, the de-esser and compressor, their SSL plug-ins, and their H-Delay. I absolutely love the Waves OneKnob series. It’s a plug-in that’s just one knob. So if you want a filter, you open up the OneKnob filter, and there’s just one knob where all it does is engage the filter. I love that concept. As you can tell, I’m a minimalist. Simple and to the point.

Does your job ever involve pitch correction for vocals?

Sure. A lot of the time, I am the one that will slap AutoTune on there, if that’s what they want. Lil Uzi Vert, he wants AutoTune on his vocals. Even singers who sing really, really well like Ariana Grande will want some tuning sometimes, and I’ll use it just for the texture. AutoTune itself actually has a sound even if it’s not technically affecting notes. When the audio goes through that particular plugin, it kind of smoothes things out. Sometimes we use a more detailed program called Melodyne where I can really get in there and tune things without it sounding too robotic.

Did you use Melodyne or AutoTune on Invasion of Privacy?

I used both. I used a touch of AutoTune on Kehlani’s vocals in “Ring” but not a lot. She’s an amazing singer. I definitely used some AutoTune on Migos’ vocals in “Drip,” because that’s what they like — that robotic, T-Pain-type sound. Throughout the album, I also used Melodyne, even on “Be Careful.” Cardi sang that hook, and I had to Melodyne her on that, just to get her notes and the sound right.

“Money” is one of my favorite songs from Invasion of Privacy. What are examples of things you tweaked there?

I do subtle things. And there are some things I didn’t touch at all at first. Like the hi-hats, I rolled off the low end and added 4db in the upper frequencies. It’s not a lot. It’s subtle, but it makes it sound crispy. The piano I left alone at first, but then I got notes back on the mix, and Craig said he wanted to feel like the piano had more “bite,” which for him, means more high end. On the 808, I used an EQ to boost at 60hz, which gives it a bit more thump. Normally, I would boost at a lower frequency, but this needed to have punch and feel more like a kick drum.

Are there particular reverbs that you like to use?

I love Audio Ease Altiverb. It’s a convolution reverb where it uses a lot of different impulse responses. They’re little reverb programs where it emulates the sounds of different rooms that engineers have loved and used over the years. It lets you see a picture of the room that it’s emulating. I love anything visual.

So let’s say there’s a church in England that they modeled the reverb after. You can pull up the reverb, and then it shows you what that room sounds like from a certain position. You can move your position around the room, and the reverb changes to match how it would sound depending on where you would be sitting in that church.

How many hands does a song pass through before it gets to you?

It depends. When I’m working with Pharrell, his engineer might gather all the files from other engineers and then send it to me as one big file. But sometimes, I get pieces from all over, and I have to put it all together myself.

With Cardi B, most of the songs were recorded by her engineer and then it was sent directly to me. But if you have a song with a lot of different people on it, that’s where it can get tricky. “I Like It” is a perfect example. If J Balvin’s engineer recorded his vocal, Bad Bunny’s engineer recorded his vocal, and then Cardi’s engineer recorded her vocal and most likely recorded most of the instruments, then I get parts from all these different engineers.

Sounds like “I Like It” took you longer to mix than normal.

Yes, it took me a full day and a half. And in the grand scheme of things, where I only had a week and a few days to get the whole album done, that took up a big chunk of time. It was such a crazy week.

What would you tell people who are looking to be better music producers at home?

A good use of your time is the internet. There are so many great teaching tools like Lynda.com, Pensado’s Place, and my alma mater Full Sail has tons of educational videos where people like myself and others talk about their craft. There’s so much stuff that a young producer or aspiring engineer can find online.

That’s something I envy with this generation. We didn’t have this. Back in the day, the only source I had for information was a set of encyclopedias! When I was a kid I went in the encyclopedia and looked up “recording studio.” That was my internet. How freaking amazing is it that you can go to Google, type in a sentence, and a whole ton of shit comes up? I think it’s one of the greatest tools of our time.