If Bruno Mars hadn’t already established himself as a bona-fide superstar by the time he released his third album, 24K Magic, in November 2016 -- with four Billboard Hot 100 No. 1s, an awe-inspiring Super Bowl performance and a record of the year Grammy win for “Uptown Funk -- his latest LP certainly set that in stone.

In addition to his recent Cardi B remix of “Finesse” creating serious buzz, Mars has earned another six Grammy nominations this year for 24K Magic, including a song of the year and record of the year nod. But while he’s worked hard for his success, there’s a little secret to how he’s dripping in finesse these days: The Stereotypes.

The producer quartet (Jonathan Yip, Ray Romulus, Jeremy Reeves and Charm) helped Mars find the exact “bounce” he was looking for on 24K Magic’s biggest hits, including the title track, “That’s What I Like” and “Finesse.” And though they’re just now receiving accolades for working with Bruno, The Stereotypes and Mars go way back. How far? When The Stereotypes started working together around 2007, their current manager, Larry Wade, was managing Bruno’s right-hand man, producer/songwriter (and Mars' The Smeezingtons cohort) Philip Lawrence.

“Philip was like, ‘Man you guys gotta meet this kid named Bruno, I’ve been working with him a lot,’” Romulus recalls to Billboard. “And that’s exactly what happened. We literally met up for a session and from then on, the rest is history.”

Their history could be even more iconic after Sunday’s Grammy Awards (Jan. 28), where they have a chance to take home a gramophone for “That’s What I Like,” which is up for both best R&B song and song of the year. (The foursome also earned a producer of the year nomination for their work with Mars and other hitmakers including Iggy Azalea ("Mo Bounce") and Lil Yachty ("Better" feat. Stefflon Don). Ahead of the big night, Billboard chatted with Yip and Romulus about their relationship with Mars, the magic of working on 24K Magic, and what it would mean to them to win with their old pal.

How did you meet Bruno?

Yip: We were introduced to him as, “You guys have to work with him. He’s crazy, he’s incredible.” And I think at that time, he might’ve just been dropped from Motown, but was trying to figure out his sound and what he was gonna do for his next steps. But when you get introduced to somebody, like when they give you that kind of intro, you’re like “Okay, he must be something.”

Romulus: I met him as Bruno Mars. I was like, “Man, that kid has a really cool name!” [Laughs.]

That’s too funny. What were your first impressions of him?

Yip: I was like, “I haven’t heard a voice this pure since Michael Jackson. His voice is so clean.” And then I started seeing him pick up a bunch of instruments and playing with them, and I was like, “God, this guy is ridiculous.”

This was in like ‘06, or something like that. He was obviously a lot younger, and not as experienced, but still very talented. So it was just watching this kid, multi-talented with a crazy voice, write songs and I was just like, “Geez, where did you come from?”

Romulus: From the day I met him, he was never supposed to be behind the scenes. This guy was supposed to be front and center from the beginning. So I think it was just a matter of time for things to align for him where, you know, he really got his shot. Once that door opened, he kicked it down and ran through and there was no stopping him.

We worked together on one session, and right away I was blown away. Just from his voice alone, I was like, “Wow, this kid is incredible.” And right then, right off the bat, we just clicked and we started like just working everyday, just trying to create songs for different artists and trying to get placements together.

What do you think is special about his songwriting and what he brings to sessions?

Yip: Talk about somebody who really just knows how to write a song. And a hit song, at that. One thing that he said to me back in the day -- this wasn’t even a song for him, we were doing a song for a different artist at the time, and we were working on the transition from the pre-hook to the hook -- and he was just like, “Give them what they want.” I always took that as, like, people want to hear dynamics. They want you to lead them in the song -- tell them the verse is here, tell them where the chorus is at. You don’t want them guessing, you want them to know where it’s at right away. And those words stuck to me the whole time: “Give them what they want.”

Romulus: For us, it was more how effortless it was creating with him. It didn’t feel like we were actually working and making songs, it just felt like we were hanging out, having conversations, and as we’re doing that we’re making the beats... he would literally have a new idea for something every second, he would just be spilling out ideas. Bouncing off ideas with him and Phillip, they were just an amazing duo to work with. So, that’s why we just stuck with that team, and we knew we had something right pretty early.

So even though years had passed and Bruno had blown up by the time you got back in the studio for 24K Magic, was it basically just like old times right away?

Romulus: It was like a reunion, we spent the first couple ours just like catching up. It’s amazing to see that no matter how much fame or success he has had... we’re still like those same young kids from the first time we jumped in the studio, just to be excited about music. It didn’t feel any different.

And then, you know, he played us “24K Magic,” and the idea that he had, and we just went right in and started working on it. He was basically like, “Hey guys, if we knock this out and kill it, I have a couple more ideas that I would love for you guys to be apart of.”

Yip: He played a lot of the stuff that he already had on the album. Immediately, we were like “Whoa. This is crazy and it’s throwback, but it’s good authentic throwback.” And he was like “Guys, I want to dance. I want it to feel like when I was back in school at a school dance. You know, in the club these days, people aren’t dancing anymore. They’re in their VIP booths with bottles, and they’re standing against the wall, or just looking at the DJ. What about times when we would be with and with a girl, or a guy and a guy, or a girl or whatever, and they’re dancing together? And not just sitting back just drinking. I want that feeling back.” It immediately excited us because we were like, “Yeah, I remember those times -- those times were awesome.”

Especially for “Finesse,” he was like, “We gotta go new jack swing. Let’s get one on here.” For me, new jack swing is like my favorite era ever, and so as we’re going along we’re just messing around making some stuff. He’s getting on the drum set, everybody is grabbing an instrument, and everybody is singing and yelling. Everybody is kind of contributing their little bit to the song, and next thing you know, we’re dripping in finesse [Laughs].

Was there a similar dance-based thing for the making of “That’s What I Like?”

Yip: He had a bunch of it, like a skeleton of it already laid out, and he was like, “We need to make this bounce.” We would just go back and forth and we were messing around with rhythms, and next thing we know, it’s hitting, it’s bouncing -- half-time, double-time. He kept saying, “It needs to make me bounce, it needs to make me move a certain way.” And he would move, and be like that’s it. This is it. He’d be like, “I don’t want it to make me move another way.”

Romulus: It felt like the whole room -- once he felt like the whole room was moving the same, he could envision everyone dancing sorta the same way to the song. Once we found that pocket that he wanted, that song was ready to go.

Yip: He’s just always moving in the studio. He’s never sitting down. He’s either thinking, and you can see him thinking, or he’s moving. I think he imagines songs as if he were performing them already.

What’s something about Bruno that fans may not know?

Romulus: He is his own biggest critic. He really, really cares. And he puts it all on the line. He’s the first one at the studio, last one to leave. Ultimately all of those decisions were up to him -- when it was ready to be released and everything like that. He put in countless hours of work even when we were gone just to make sure it was at the standard he wanted it to be.

Yip: Last week, working on performance stuff, I was there ‘til five in the morning, and our partner Charm and Bruno were there until eight in the morning. He is such a perfectionist. And I’ve never seen anyone who is like that so much. He’ll be like “That’s not right. Something is not right.” And he’ll stay there until he gets it right. And then it goes.

He’s the real deal for a reason because he works at it. He’s obviously naturally talented, but to get as good as he is, you have to work for it too, and he does.

How would it feel to win a Grammy with Bruno?

Yip: We’ve been trying not to think about it, and to stay busy and keep our heads down and not let that consume our life. But it’s definitely approaching pretty quickly, so we’re gonna have to start thinking about it. If we do think about it, It’s kind of crazy. Because we started this together, and to be here in this moment together just makes it extra cool and extra special. This is what we imagined as the original squad. We have tons of videos and there’s footage online of us making music when we were like babies. And now we’re all getting older, and what I would like to think, is the best part of our career right now.

Romulus: It will be just amazing because it will be everything coming full circle. At the end of the day, it’s a matter of time for that to happen, but it’s amazing that it is happening right now -- just blessed and appreciative of the moment.

How do you think you’d celebrate together?

Romulus: To party... hard. [Laughs.] That is the plan.

Yip: I have no idea. Yes, definitely partying [Laughs]. We’ve been to the Grammy’s before, but I honestly don’t know how to feel and how we will feel. That’s something where if we do win, I’m gonna ask him like, “Yo, What are we doing?” And then let him lead. Bruno’s used to this, so maybe it’s something that he could let us in on ‘cause I have no idea.

We’ve hung out for no celebration before and it was pretty cool, so I can only imagine what it is if it’s one of the biggest nights in music. It’s a blessing for sure to be a part of it, and for him to ask us come along on this journey. It’s been a career-defining and enlightening moment for us.