Katy Perry Exploring 'Deep' Themes On New Music

Katy Perry's new single, "Part of Me," certainly shows a not-often-explored side of the pop singer. The scathing break-up track is all about the end of a great love and the empowerment one feels after watching that person walk away. It's darker than "California Gurls," that's for sure.

Considering the timing of the track's release, it's hard not to think that it's about her former husband, Russell Brand. It's the lead single off her March release, Teenage Dream: The Complete Confection, and it kicks off a new era of songwriting for the usually candy-coated pop star, her pal and frequent collaborator Bonnie McKee told last week, just days before she dropped the track.

"I've been working with Katy Perry a lot more, so I'm excited for what we have coming out next," she explained. The twosome already have a long history with one another having already cooked up hits like "California Gurls," "Teenage Dream" and "Last Friday Night (T.G.I.F.)" off 2010's Teenage Dream.

"I'm working with Katy and it's great," she continued. "I'm really excited and I think everyone is going to really relate to and love what she's doing next. It's kind of a departure from what she's been doing in the past. We are a great team when we write together because we don't let each other settle; every single line is a philosophical debate."

That means that while their past collaborations have focused on the sugary-sweet, this time they are looking deeper for their lyrical content. "She's going through some major life changes, so it's not all about bubble gum and fun; it's real and it's deep and she has a lot to say. So I think people are anxious to hear it," she said, adding that while there are those people who are rooting for the star, there will also always be the haters.

"You know what? The numbers don't lie," she said to those folks. "Katy Perry is a star for the people ... she's unstoppable and she's proven that."

What do you think of "Part of Me"? Leave your review in the comments section!