Olivia Newton-John sat in as a guest judge during American Idol tryouts in Los Angeles on Tuesday – and had nothing but kind words for the hopefuls.
"Some of them are very young and they're green, but you can see their potential," she tells the Associated Press. "They have a different voice or a different way of presenting themselves."
The Grease star, who turned 58 on Tuesday, says she understood how the contestants must be feeling, having jump-started her own career on the Australian TV talent show Sing, Sing, Sing in the '60s.
The sting of rejection can be "terrible," she says, but sometimes it's for the best. "I always remember what it was like for me and what it would have felt like to be told no. So I do feel for them," she says. "It's hard. But sometimes it's probably kinder for them, because they won't pursue something they don't really have the talent for."
Newton-John joined Simon Cowell, Randy Jackson, Paula Abdul and Ryan Seacrest at the third-round auditions, where she was presented with a cake for her birthday.
The FOX talent show returns for its sixth season in January. Other celebrity guest judges for the current round of auditions include Jewel in Minneapolis and songwriter Carole Bayer Sager in New York City.