Britney Spears and Demi Lovato made their debut on The X Factor as the show premiered on Wednesday (12Sep12).
The singers joined music moguls Simon Cowell and L.A. Reid on the judging panel in their first taped audition episode, replacing ousted stars Paula Abdul and Nicole Scherzinger.
Spears proved to be an acid-tongued critic, telling 50-year-old contestant Shawn Armenta, "I wanna know who let you onstage. I feel uncomfortable with you even staring at me," and ranting at another, "I felt like I was listening to Alvin and the Chipmunks."
Lovato also took to her new role and ran onstage to hug Jillian Jensen, who was bullied at school, during one of the show's most poignant moments.
She told the teenager, "I've made it through it. I know you can too."
Spears counted down the hours to her TV debut in a series of posts on her Twitter.com page, and subsequently told fans, "My hard work is coming to life. Happy moment!... Hope u (sic) all enjoyed that!! So blessed to be a part of The X Factor USA & to have all of your support."