Jennifer Lopez shakes her moneymaker at Verizon Center

Jennifer Lopezs name was atop the bill Saturday at Verizon Center, but her derriere was the star of the show. Lopez spent much of her time on stage with her back to the audience. Shes not the first performer to do that. Van Morrison, for example, often turns away from the crowd, just to show hes an ass; Lopez turns away just to show off, well, you get the rest.

Shortly after coming to the stage to Never Gonna Give Up, one of many super-produced, techno-driven dance numbers in the hour-long set, Lopez peeled off all sorts of furry accessories to reveal a sequined catsuit that left much of her backside uncovered. While flashbulbs popped, lasers shot behind her and fireworks blew up overhead, Lopez gyrated and jumped and in various and very athletic ways shook her moneymaker at the fans, who roared their approval.

Lopez, who turned 43 last week, has had an amazing show business career. She went from a background dancer on the television series In Living Color to feature film star (Selena) to, well, just plain celebrity. Shes great at that gig: Forbes ranked her as 2012s top celebrity, just above Oprah. Lopez has used that power to do what she wants, dropping what looks like an easy job as judge on American Idol to get back to performing. And she clearly has prepared for the rigors of the road: Her abs were on display for much! of the night also, and gravity has apparently yet to find them.

She only briefly got in touch with her Latin side, sporting a mariachi-esque costume for a few bars of Lets Get Loud before ripping it off to reveal another sequined catsuit. She relied on a video of Flo Rida to accompany her on Goin In, and a cinematic version of Pitbull showed up onscreen to shout along with Lopez on On the Floor. While the production and the arrangements and the delivery are all grandiose, it wouldnt take Simon Cowell to point out that the melodies were just mediocre and that her singing was essentially irrelevant. On many tunes, it appeared as if Lopez wasnt singing at all, despite the vocals coming through the house PA.

Lopez, as divas are wont to do, took a lot of breaks, to change costume and gas up for the next dance number. The audience sat through bad videos on the arenas big screens during those pauses, including one that was just a series of Hallmarky slogans, including Love for Me Is a Journey, Not a Destination and You Must Love Yourself to Truly Love Another. Another simply had her canoodling with her latest companion, Casper Smart, who also is her choreographer. Hes 25; Lopez graduated high school 25 years ago. Lucky him.

On Thursday, Sarah Kaufmans Dance of Life series looks at the behind-the-scenes choreography of riggers and stagehands as they set up 18 trucks worth of gear needed to put on the J-Lo concert.

McKenna is a freelance writer.