In this clip from last night's Rolling Stone after-party at the American Music Awards in Los Angeles, stars arrive on the red carpet and chat about their favorite performances of the night. "Katy Perry played acoustic. It was really risky with a big production show," says the Eagles' Joe Walsh. "And she just nailed it." Adam Lambert raved about fellow American Idol alum Kelly Clarkon's performance. "She was very at ease and very comfortable on stage like she always is," he says.