Rick Rubin, Russell Simmons, Lyor Cohen, Jay Z, L.A. Reid...Def Jam has seen a succession of iconic leaders during its 30 years, and on April 1, Steve Bartels found himself next in line. And while his sleek corner office in the Midtown Manhattan building of Universal Music Group (UMG) is worlds away (if only 50-odd blocks) from the New York University dorm where Rubin famously founded the label in 1984, Bartels brings his own bona fides to the job. Born in Ohio but raised in Spring Valley, N.Y., he entered the music business as a DJ around the time Def Jam was born. A job in dance promotion at A&M Records, where he was hired by the late legendary executive Charlie Minor, led to a decade each at Arista and Island Def Jam, working with Clive Davis and Reid, the execs who, with Minor, he considers his music business mentors. Bartels' restless nature has seen him rise through the ranks and, during the past 10 years, he has played a pivotal role in the careers of Jay Z, Kanye West, Rihanna, Fall Out Boy and Justin Bieber, to name just a few. Now 51, the married father of two (a son, 16, and a daughter, 10) is at the helm of a label with a catalog that includes LL Cool J, Public Enemy, Nas, Ludacris and The Roots, among more recent signings like 2 Chainz, Frank Ocean, Iggy Azalea, YG, Jeremih and Jhene Aiko. Many of those acts will appear at Brooklyn's Barclays Center on Oct. 16 at the 30th-anniversary concert for the label, which is also being celebrated with a lavish box set compiled by Rubin and Ahmir "Questlove" Thompson.

Bartels' connection to his artists is evident in the photographs decorating his office, including multiple shots of the label's resident diva, Mariah Carey, whom he simply calls "incomparable." After eagerly spinning new songs from Axwell & Ingrosso, Roc Nation signing Sam Romans and, not least, a new song from Bieber that finds the singer heading in an unexpected direction, the CEO and cycling enthusiast talked to Billboard about Def Jam's anniversary, its future and his wild weekend in Tokyo.

You just got back from raving it up at the Ultra Music Festival in Tokyo. Is that appropriate behavior for a CEO?

(Laughs.) I think it's a great look for a CEO -- especially when you've got three of your new signings [Afrojack, Alesso and Axwell & Ingrosso] headlining the closing night. It was great -- sold out, 30,000 people there. I could see it possibly doubling in size next year. But I just went to support my guys -- I was awake for 24 hours. We went to dinner and were out all night.

Do those signings mean you're pushing harder into dance music?

I've always supported dance music and will continue to. Their music is unbelievable, and they are absolutely a fit for Def Jam. Now, will we sign 20 more DJs? If they're great and fit that criteria, I will never rule anything out. I want to pick up the philosophy that Russell and Rick had in terms of diversity and breaking genres.

Bartels' "Special Presentation" Lifetime Achievement MTV Video Music Award.

What's in store for the Def Jam ­celebration? Will it go as far back as, say, the label's first release, T La Rock?

A lot of our original pioneers will be performing. You'd be amazed at how many people are coming out of the woodwork: "I'll do a song! I'll do a couple of songs!" There are some ideas we have that we're not sure if they're going to come off yet, and I have real hopes for some moments not currently on the slate.

Island and Def Jam separated earlier this year into two stand-alone labels. Was that split by genre?

Not at all. We're not genre-specific. The premise was that the artists went where they were signed, although Bieber, Iggy Azalea and Afrojack did come over to Def Jam. But for a lot of the other artists, I was like, "Wow, all these guys I've worked with...Fall Out Boy, The Killers." We broke Avicii and he's on Island. There's an emotion to it, but I've moved forward.

How has your job changed during the past 10 years?

A lot - it's much broader than when I came in. I'm involved more closely with artist relations and A&R and setting the tone with [UMG chairman] Lucian Grainge and Michele [Anthony, UMG executive vp], and making sure we're technologically poised to carry the label into whatever's coming next.

What sort of outreach did you do with retailers before Jay Z's deal for Magna Carta ... Holy Grail in 2013, where anyone with a Samsung phone got the album for free?

We were upfront very early with them. I went to retailers with John Meneilly, who was his manager at the time, and [Island Def Jam executive vp] Pat Monaco. I said, "This is going to happen, this is why it's happening, this is the amount of advertising Jay is getting." And we figured out something unique and exclusive for [retailers like] Target and Best Buy, to make the accounts feel special. It wasn't anything overly over the top, but it was enough where they got it and were very happy with the honesty.

A plaque showing all the countries in the world where Jay Z and Kanye West's Watch the Throne hit No. 1. "There were only a couple made," says Bartels.

What can you say about the new Kanye West album?

It sounds incredible. He's focused, energetic, happy and making unbelievably great music. Kanye always wants to make sure that when it actually arrives it's at the best possible place it could be, that the first song is as big as the last. He's the absolute bar of perfection in terms of that. I tell him all the time: Some of his previous albums are still testing out in the marketplace as high, if not higher, than when they first came out because the music is still fresh to people.

What do you think happened with Carey's latest album, which spent just eight weeks on the Billboard 100, her shortest stay for a studio LP?

Listen, sometimes an artist -- and in the case of Mariah, an artist I've worked with for 10 years -- makes an amazing album that just doesn't connect with the audience. Of course that is very disappointing, but it would be impossible to pinpoint that down to just one thing. I've enjoyed incredible success with Mariah and many of those hit songs and albums have made Billboard history. But this latest effort just didn't go all the way.

What are some your most "I can't believe this is happening" moments over the years?

Oh, that happens to me a lot. Probably with Rihanna when we decided to put together the 777 tour, where we chartered a plane, brought along press and stopped for shows in seven cities around the world. It was very disruptive and very cool -- and she ended up getting her first number-one album. Another was when I came back from vacation and Jay Z called and said "I think I'm ready for you to hear my album [Magna Carta]." I went into the studio and all these artists were there -- Justin Timberlake, Pharrell, DJ Khaled. I was just sitting there and Jay leaned over and said, "We're gonna do this album with you." Or Kanye speaking to me about his vision of Yeezus and how he wanted to [preview the album via video projections on buildings in various cities], and to have it be the most critically acclaimed album of the year. Or being at the Swedish House Mafia's last concert in Miami [in 2013] and seeing that explosive power of music and culture. There are so many.

Do you remember the first time you met Rihanna?

She was signed in [then Def Jam president] Jay Z's office — I remember her eyes and how amazing her presence was in the room. I remember taking ["Pon de Replay"] to a studio in midtown, this was probably 2006, I think LA Reid was there, and we played it to a bunch of radio programmers. Everybody was like, "I've gotta leave and put this on the radio right away."

How do you handle an artist who has become overexposed, like Bieber arguably has?

I don't think he is overexposed. I think he had the unfortunate task of growing up in front of the world. I don't know how you could be judged by every left turn, every shoelace you tie -- it's a very unfair trajectory. It's part of what comes with [stardom], but for somebody to grow up through that...being with him and [seeing paparazzi] bait him and goad him, and having people literally throw themselves across the car -- I think with much scrutiny, anything you do is going to get embellished or highlighted to a degree that maybe isn't fair.

Do you still DJ?

I DJ in my music room of my house. I'd love to [do more], and I've had people tell me, "Let's get you out there!" I just don't have time. But I'd love to go to a big club and ... "Wait, who is that up there? Oh my God, it's Steve."

A version of this article first appeared in the Oct. 18 issue of Billboard.