Britney Spears and Demi Lovato have been the subject of major media scrutiny in their day. Finally, the two new additions to X Factor 's panel are the ones doing the judging.

Pop princess Spears, 30, and former Disney star Lovato, 20, replaced last season's Paula Abdul and Nicole Scherzinger. On Wednesday, they joined music producer L.A. Reid and X Factor executive producer Simon Cowell at the judges' table for their first taped audition show. (Live comes later.)

And Spears was not that innocent, her low-cut red dress and cleavage-baring pink number aside. After giving a nod of approval to 21-year-old Paige Thomas ("Holy cow, yes,"), she started denying contestants with grimaces and a dry delivery. "I thought it was just kind of bad," she told one. "The singing came in, and it wasn't very nice," she told another. "I felt like I was listening to Alvin and the Chipmunks," was followed by "I think you're like Vanilla Ice meets Lauryn Hill meets West Side Story." And the winning comment for Night 1: "I wanna know who let you onstage. I feel uncomfortable with you even staring at me."

She wasn't all cutting, calling some contestants "bright and beautiful," "utterly adorable" and "absolutely incredible." And saying no to a 32-year-old who had recorded a duet with Spears "like 10 years ago," she said, proved particularly tough. "Maybe you've gone through a lot of hardships and battles, but your voice isn't up to the bar of The X Factor," she told him gently.

While Spears was somewhat reserved, Lovato cheerily took control, asking the singers to introduce themselves and handing the mike to Cowell to comment on the performances. As the only judge too young to drink, she related well to the teenage contestants, complimenting them on their glitter, cuteness, lipstick and stage presence.

She felt a connection with one contestant in particular. Jillian Jensen, 19, who was bullied in school and has the same "stay strong" tattoo as Lovato, performed a tearful, pain-racked number. After she sang, Lovato ran onstage, hugged the crying fan, and said, "I've made it through it. I know you can too." There wasn't a dry eye in the house.

Surprisingly, that included Cowell, who for most of the evening was his old, snarky self, making outrageous comments to contestants he disliked, including, "It kind of sounded like you were dying," and "You know those boy bands five years ago, there's always one that didn't sing. That's you." But the girls helped bring out his softer side, like when cross-dressing contestant Quatrele Da'an Smith, 21, performed in a ripped wedding dress and veil, and Cowell was immediately dismissive.

After Lovato and Spears professed their love for Smith, however, Cowell softened: "If you imagine Madonna, Bobby Brown and Dracula had a child, it would be you. But in a weird way, I quite like it. Sometimes I have to embrace the madness. I'm gonna say yes."

To Lovato, Cowell was paternal, telling her to stop flirting with boys. He enjoyed Spears' dismissals of contestants. "You're good at this," he told her. Reid said nothing controversial, but, as he did last season, he compared singers to artists who have "walked though my door." In this round he found singers who resembled Rihanna and Justin Bieber, in his opinion.

The premiere week continues with an hourlong show Thursday (8 ET/PT, Fox)

USA Today