Katy Perry 'maturing as a musician'

Katy Perry is transforming from a "bubblegum pop star" to a "grown-up" singer.

The singer is currently dating John Mayer, with claims their romance is getting very serious.

Katy was previously married to Russell Brand, with her wild lifestyle said to be one of the reasons she split from the recovering addict.

The 28-year-old star has apparently transformed since she started seeing John, who is also helping her turn her life around.

"She used to party all night, but she's put the wild life behind her for John," an insider told National Enquirer. "He's also helping Katy segue from a bubblegum pop star into a more grown-up musician."

Earlier this year, Katy raised eyebrows when she was spotted deep in conversation with Dominic Howard, who is the drummer with rock band Muse.

The conversation was entirely innocent though, with Katy simply asking the musician for tips on staying healthy.

John has also altered since he started romancing Katy last year. He was once known for his relaxed attire and long locks, but has been looking more dapper of late. That is said to be in part because he has started helping himself to some of Katy's grooming products.

"John is almost obsessed with looking good, and he doesn't have the least problem using Katy's grooming products to get his handsome on," a source recently said.