Almost everyone interviewed for this piece got the memo about a more mature Bieber. The most recognizable teenager in the world turned 18 on March 1, after all, and this is a pivotal moment as he aims to make the leap from tween heartthrob to enduring icon.

One key person, however, bristles when asked about that transition – his manager, Scott “Scooter” Braun, the maverick who famously found Bieber on the Internet at age 13 and, together with Usher, signed him to a joint deal through Raymond Braun Media Group. “Adult artist? Just because he’s legal now doesn’t mean he’s an adult,” Braun says. “He still needs guidance; he’s still finding his way. He’s no longer a boy, but he’s definitely not yet a man.” And his music, image and how he carries himself – spontaneous bursts of moonwalking and all – reflect that, Braun says.

Backstage in his dressing room at the MGM Grand Garden Arena in Las Vegas for rehearsals at the Billboard Music Awards, brandishing a glistening new rose gold Rolex on one arm, a pair of gold chains around his neck (one with a gold whistle charm dangling from it), Bieber is clad all in black the second time we meet for a sitdown interview-black slouchy jeans, T-shirt and ski cap fully covering that famous hair, only a red bandana in his left back pocket adding a pop of color to the ensemble. Later this evening he’ll be practicing his high-jumping choreographed performance of “Boyfriend” that will ultimately net him a “most exhilarating performance” award from fans who voted online during the actual show – it’s also the first taste of what’s to come on his upcoming 125-date world tour, for which he’s guaranteed a cool $80 million. And not without cause: Two weeks after we talk, all 49 North American dates will sell out within one hour, with two nights at New York’s Madison Square Garden going in less than a minute. But right now he’s here to talk up his highly anticipated (by more than 43.9 million Facebook fans, at least) album, “Believe.”

His debut release, 2010’s “My World 2.0,” and subsequent remix album “Never Say Never: The Remixes” and 2011’s holiday set “Under the Mistletoe,” all debuted at No. 1. Embarking on his all-important proper sophomore album, he had some formidable goals – not just branching out to new markets and age brackets, but reaching for the unparalleled artistry of one of pop’s all-time legends: “Michael Jackson is my inspiration,” Bieber says between bites of a Big Mac. “For me, he’s the greatest – he’s the King of Pop – and everything I do, I do to be the greatest.”

To help him fulfill those aspirations, he enlisted several edgy hitmakers, including Posner, Diplo and Zedd – along with pop stalwarts like Max Martin – and settled into the recording studio for four tracks with the man who produced Jackson’s last No. 1 hit, “Rock My World,” Rodney Jerkins.

The first thing Jerkins did was show his new wunderkind never-released footage of Jackson in action in the studio. “I wanted him to see Michael’s passion in the studio – we all know he had that passion onstage in front of 60,000 people, but he also had it alone in the booth. I’ve been fortunate enough to work with a few greats that had that passion, so I know what it is when I see it. And Justin has what it takes, absolutely.”

Bieber’s directive was clear to Jerkins: pop with urban elements. “Because he’s also a drummer, he wanted to make sure that the rhythms were there as well as the pop melodies on top. We really focused on those combinations,” Jerkins says.

“As Long As You Love Me” – Bieber’s personal favorite track on “Believe” – is a perfect example of a song that will speak to his core fans with its indelible melodies, and has the ability to reach new listeners, says Jerkins, who added dubstep sonics to the production on Bieber’s urging. “There’s nothing like it,” says Bieber, who got hooked on dubstep on a trip to London, where it was all over the airwaves. And from the global dance beats pulsing throughout many of the album’s tracks, it sounds like his mentor Usher’s recent work has also left an imprint on Bieber.

But for Jerkins, the most significant of their collaborations is “Die in Your Arms,” which clearly evokes a young Jackson and focuses on Bieber’s voice. “The mission on that one was to have Justin make a statement vocally,” Jerkins says. “In making this transition, the one thing he has to prove to people is, ‘Listen, I’m a real singer.’ This isn’t about three notes here; this is about him showcasing his voice. It’s not the easiest song to sing-it’s a real singer’s song with Sam Cooke-style melodies in the chorus. And he nailed it.”

While making this leap, understandably there are going to be some growing pains along the way. Bieber and his team smartly got ahead of the game by allowing him to be shown having taken a physical beating in a Complex magazine cover that featured the squeaky clean singer with a black eye, ravaged to a highly stylized pulp in a boxing match. In a recent GQ profile he took a different kind of drumming, the magazine using the pop star as a bit of a punching bag. But it’s all par for the course for a guy whose career was birthed online.

“No one in the history of the world has ever grown up with the pressure that he has, being a solo artist that young, that famous, in a world with technology that exposes us 24-7,” Braun says, noting that unlike Jackson, who had his brothers behind him, or Justin Timberlake, who could rely on the support of his fellow ‘N Syncers, Bieber went it alone – in an unprecedented era of Twitter, Facebook and camera phones. “He was literally going through puberty in front of the entire world, with everyone expecting something from him and a lot people waiting for him to screw up. He’s a fighter. I’m proud of him – how’s he’s stayed true to himself and taken control of the entire situation.”

Even the coolest of heads can lose it when confronted with the paparazzi, though. Bieber made news on May 27 when he got into a scuffle with a photographer who reportedly blocked his way as he and girlfriend Selena Gomez were exiting a shopping mall parking lot in Calabasas, Calif. Still, Bieber remains steadfastly appreciative on the pros and cons of growing up in this hyper-digital era.

“Your life is out there a lot more, especially nowadays when everybody has a HD camera phone on them at all times,” Bieber says. “But my whole career launched from the Internet, so without it, I feel like I wouldn’t even be here. I owe a lot of my success to social media, to Twitter, to YouTube and Facebook. It is also a great way to interact with fans.”

And, by this point, he’s a pro at it, on the front lines himself in rallying the Beliebers for the launch of “Believe.” With more than 22.3 million followers on Twitter, it’s no surprise he took home the gold trophy for top social artist at the Billboard Music Awards. “For Justin in particular, it really all starts with the fans,” IDJMG VP of marketing David Grant says. “He engages with them on a daily basis through his social media.”

That’s been extremely useful to the label, says IDJMG president/COO Steve Bartels, who points out that the fans have been integral in the marketing of this album since before the first single was even available.

“Justin’s fan base is very loyal and it is about giving them the opportunity to be involved in the social media campaigns,” Bartels says. “For example, we encouraged the fans to choose Justin’s single artwork for ‘Boyfriend.’ [They voted on two options through Twitter using hashtags.] This is one small example of how we keep the fans very involved in many aspects of the campaign. Their opinions matter to Justin, and to us.” (Those opinions matter to Billboard as well-Bieber fans chose which cover image adorns this issue through Facebook.)