Katy Perry at Staples Center: 5 thoughts on her hometown show

Declaring that “nobody reps this place harder than I do,� Katy Perry took over Staples Center on Friday night for the first of two hometown concerts on her Prismatic World Tour.

“It doesn’t matter if this is show No. 65,� she told the arena full of California gurls (which included, Perry said, her 93-year-old grandmother). “You’re not just another number.� Here are five thoughts on the evening:

1. Only a pop star with as many hits as Perry would dispense one of her biggest right out of the gate, as the singer did with a highly aerobic rendition of “Roar� that had her jumping glow-in-the-dark rope at one point. The bouncy anthem of self-affirmation, which also opened last year’s “Prism� album, set the cheerfully optimistic tone of the two-hour production to come.

But it served notice as well to any casual fans in the house -- the chaperones, in other words -- that they were likely to know every song Perry planned to play.

2. She wasn’t kidding with the aerobics. Perry sang “Part of Me� while marching on a treadmill and disappeared through a trap door during “Dark Horse� only to reemerge seconds later through another across the arena floor.

“Remember, I’m just one of you,� she said after “Wide Awake,� and among the reasons that was nonsense was her uncommon stamina.

3. Inspired in part by Perry’s failed marriage to the English comedian Russell Brand, “Prism� attracted mixed reviews for the way it complemented her reliably spirited party songs -- who could hate “Birthday�? -- with squishier, more ostensibly introspective tunes. (Consult Gawker’s comprehensive rundown of “all 226 cliches uttered by Katy Perry on her new album� for a sense of the scorn.)

At Staples, though, she moved through “Love Me� and “This Moment� with as much forward momentum as she did “California Gurls� and “This Is How We Do�; they weren’t vegetables we had to choke down before being given dessert.

4. Which isn’t to say that vegetables were absent from the menu.

Midway through the concert, Perry and several members of her backing band moved to the end of a long runway for a semi-acoustic mini-set that began with a convincing take on “By the Grace of God,� the much-noted “Prism� closer in which Perry appears to allude to an attempted suicide. Her singing was strong here, and you couldn’t help but be charmed when she took a moment after the song to soak in the crowd’s applause.

“Sometimes it’s a little overwhelming because I used to play the Hotel Café,� she said, referring to the tiny Cahuenga Boulevard joint where she got her start. But then she brought to the stage Ferras, an L.A.-based singer signed to Perry’s new record label, and together they brought the show to a standstill with a plodding piano ballad that tasted like limp asparagus.

5. But then: dessert! As she’d hinted at the outset, Perry has a deep bag of Top 40 radio staples, and Friday she saved a bunch of them for a delirious home stretch that started with a mega-mix of late-’80s/early-’90s club tracks (“Pump Up the Jam,� “Finally,� etc.) that transformed into her own pitch-perfect homage to that era, “Walking on Air.�

Then it was banger after banger, “This Is How We Do� into “Last Friday Night (T.G.I.F.)� into “Teenage Dream,� which she dedicated to all the moms and dads getting tipsy. The jam? Definitively pumped.

Twitter: @mikaelwood