In the lead-up to the release of Justin Bieber's album Believe, there has been a lot of talk about how much the 18-year-old has grown up since he dropped his first EP, My World, back in 2009. Sure, he is actually older, but the conversation has also been focused on how his music sounds more mature. He no longer seems to be crafting sugary-sweet tracks like "Baby."

The pop star will celebrate his mature new album during "Bieber Live," airing Tuesday at 7:30 p.m. ET/PT on MTV. Bieber will join Sway and 100 lucky fans for an interview and a pair of performances.

Adding to his growth is the fact that in the two and a half years since that debut release, Bieber has quite literally done it all. He's toured the world (several times over), topped the charts, won a lot of awards, fallen in love, become a boss to his own artist, owned the box office, befriended some of the biggest MCs in the game, vowed to "Never Say Never" and, yes, became legal.

As tiring as it may sound to be Justin Bieber, his manager, Scooter Braun, notes that when the singer sat down to make the album, he didn't want to rush it or be lazy about it. He wanted it to be perfect. His experiences are not only helping shape him as an artist but also helping him mature as one.

"You know, I think a lot of times with big superstars, they don't always deliver on that big album. They don't meet the expectation ... sometimes it's because they're superstars," Braun explained to MTV News. "Maybe they think they know it all and they don't want to listen to anyone else's input, and sometimes that works and sometimes that doesn't.

"Justin was really humble about this," he continued. "He probably wrote 200 songs and we just kept working and working and narrowing it down. And there were so many records that didn't even make it that we'll save for something else. I think when it was all said and done, there wasn't one person who listened to that album all the whole way through and thought that we didn't have something special and really great and something that didn't just reach the teenagers, but everyone — without losing the teenagers."

The album certainly has been teased for quite some time. The buzz began to really pick up around the time of the release of his holiday album in 2011, when he dropped the name Justin Timberlake as his template for career evolution, setting the bar quite high. "I'm proudest of Justin with this album 'cause I think he delivered," Braun said. "For a superstar to deliver means a lot."

Others who worked with Bieber on the release told MTV News during the recording process that it was important for him to make music that would help expand his brand beyond the tween and teen market. A big part of Bieber's musical evolution, however, is about making sure no one gets alienated.

"The only conversation we've had about Justin's album that we're about to do is it's really important that it's the proper transition because we've seen him [with] 'Baby,' now we're watching him grow up," his vocal producer, Kuk Harrell, told MTV News back in November. "And we can't just throw him into the adult game right away. It has to be the proper transition. There's a record in between."

That mission to help Bieber make the right choices as an adult artist was certainly priority number one when Bieber hit the studio with Mike Posner to work on the album's lead single, "Boyfriend." "I think our goal was to make something that me and my friends could listen to in the car," Posner explained in March. "I think we've all known Justin since he was 13, and that's not the kid I was in the studio with anymore. He's an 18-year-old. He skateboards with Lil Wayne and hangs out with Lil Twist. Those are his homies. And he listens to hip-hop and he's a really cool kid. He's not like a corny guy.

"So I wanted to make something that reflected who he is now and who he is going to continue to be," Posner continued. "I think people have been waiting [for] when he's going to turn that corner, and the time is now."

Listening to his album, it's clear that Bieber is trying out new sounds, from dance to R&B and everything in between. But he also just plain sounds different. His voice is deeper than it was when he first started making music. That register change is something he commented on in a recent interview with MTV News.

"It's really deep," he joked. "The thing is, I'd always put out random songs and give it to my fans, and when my voice was changing I was doing that. So they didn't randomly just hear [it and go], 'He's got a deep voice now.' It was gradual. They didn't realize it that much. It just kind of happened. The tone is still the same. It's just deeper and sexier."

In the end, while it may seem like he's taking a cut from another pop star named Justin, Bieber is actually focused on following yet another megastar's template for success.

"He's growing and so is his music," Braun said. "And I don't think he's transitioning and losing any fans. I think he's just growing. We always study Michael Jackson and the thing I loved about his career is he never lost that 2-year-old that bounced to his music. But at the same time, you'd go to a club and there were adults bouncing also. And I think that's what we want to do with Justin."

Don't miss "Bieber Live" on Tuesday at 7:30 p.m. ET/PT on MTV. Get into the conversation via Twitter using the hash tag #BieberLive!