Justin Bieber says his music is more adult because he himself is "maturing."

The teen heartthrob has a legion of young female fans but the 18-year-old is now trying to appeal to older audiences.

The Baby star, whose new track Boyfriend is released on iTunes today, says he wanted to mix up his sound a little bit.

"I'm maturing, and my music is maturing, so I wanted to do something different," he told USA Today. "I've got a lot of great collaborators working with me, and we're thinking outside the box."

The singer, who is currently dating Selena Gomez added that he was "very competitive" and wants his fans "to get the best."

"They made me who I am," he mused.

Island Def Jam Music Group president Steve Bartels added that Justin's new sound will have a wider reach.

"I have a daughter who is eight and has always loved Justin, but what's interesting is that when I played Boyfriend for my 14-year-old son, he thought it was cool," Steve shared.

"I think Justin will hold on to his core crowd but also win new fans."

Boyfriend is released today and Justin's new album Believe will hit shelves this summer.