An infuriatingly catchy Katy Perry

A number of girls strolled around the Wells Fargo Center Friday night in lollipop and cupcake-studded brassieres. Also frequently sighted were peppermint-striped and fruit-inspired dresses, blue wigs, neon mini skirts and LED-lit cotton candy.

It was Philadelphia stop of pop star Katy Perry's nine-month "California Dreams" tour and slightly bizarre outfits with lots of sequins turned out to be the norm.

Since the release of her 2008 chart-topping album "One of the Boys," the 26-year-old singer has transformed herself into a global celebrity. But in an era of self-made YouTube stars like Justin Bieber and Rebecca Black, Perry is a bit of a throwback to the early days of the recording industry. She was a girl with talent and desire, who cut short her attempts to be a gospel singer in favor of being molded into a pop star by music industry professionals.

It would be an understatement to say that the change was successful. Even if her name isn't instantly recognizable, her songs are. Not only are they seemingly everywhere, but they're almost infuriatingly catchy. They're pop anthems: emotional, upbeat, bombastic and full of joie de vivre.

And though Perry, along with her two backup singers, eight dancers and full band, has been performing the exact same "California Dreams" performance for four months now, she pulled it off with vigor, passion and whimsy Friday night, with nary a scent of fatigue.

A bit after 9 p.m., onto a stage decked out in lollipop and candy cane staircases, cotton-candy bordered projection screens and gumdrop cutouts, Perry emerged. Wearing a red-and-white dress with twirling peppermint, she launched into the title track from her 2010 sophomore album, "Teenage Dream."

The crowd - mainly females of all ages, plus a smattering of love-struck junior-high boys, boyfriends, husbands and gay men - was ecstatic. Throughout the night, they belted out the lyrics along with Perry, dancing in the aisles until security forced them back to their seats.

Her two-hour performance covered all her hits and then some, plus a few "MTV Unplugged"-style interpretations of tunes like Willow Smith's "I Whip My Hair" and Jay-Z's "Big Pimpin'." Also making an appearance were confetti, pyrotechnics, multiple costume changes, a whipped cream bazooka and a cotton-candy cloud that hovered over the audience with Perry perched on top.

Perry's whimsical and humanizing stage banter, along with the performance's attention to detail and well-played effort to create a fairy-tale world, left a very satisfied crowd. From the choreographed dance routines to the well-executed special effects, it was a top-notch performance that left the audience still singing Perry's songs long after the last notes of her closing song "California Gurls."