How Is Katy Perry Channeling Rocky Balboa?

Songwriter Bonnie McKee tells MTV News how Katy's progressing like the boxer on 'Roar.'

Katy Perry just might be channeling famed cinema underdog, boxer Rocky Balboa, on her new single, "Roar." That's according to songwriter Bonnie McKee, who co-wrote the track with Perry.

"It was just kind of a natural progression for her. She's grown up and she's been through a lot and it seemed like the right thing to do," McKee explained to MTV News on Monday (August 12).

Perry has certainly made it clear she is no longer a candy-coated California Gurl in the lead-up to the song's release, having burned her blue wig and also buried that persona in the ground.

But, McKee notes, "It wasn't like a conscious decision, like 'Hey, let's not do something cutesy.' It is very 'Rocky.' Like I said she's been through a lot, so it makes sense."

McKee, who has called Perry her "soul mate," recalled the circumstances in which the two wrote the track. "We wrote it, I think, it was the spring up in [Perry's hometown of] Santa Barbara [California]. It was a blast; it's always fun to go up there," she said. "We go up there and we camp out in her hometown and kind of get into the vibe."

The fierce females then headed to the studio and enlisted super-producers Dr. Luke, Max Martin and Cirkut. And, as soon as they laid it down, they knew they had made pop music gold. "It was just one of those moments where there was magic in the studio," she said. "I think it's a really unique feeling when you know you've captured lightning in a bottle and I feel like we've definitely did that."

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Considering that Perry loves cats, did she consciously make so many references to felines with "Roar?" McKee said, "Tigers have always been my spirit animal ... and you know she's got the Katy Cats, so it makes sense that it would be feline driven. I think the 'eye of the tiger' [lyric] is a pretty strong one and that seems to be the one that people are going to remember."

The same day that Katy officially released the song, she also dropped a lyric video for the track, which as it turns out, also features a cat. "Roar" is the lead single off her October 22 album release, Prism. Perry is also set to take the stage at the 2013 MTV Video Music Awards where she will perform "Roar" for the first time. The show takes place on August 25, live from Brooklyn's Barclays Center.