The search is still on for the next American Idol but, before continuing with auditions, Sunday's episode took a trip down memory lane , recollecting how two modern-day superstars, Carrie Underwood and Gabby Barrett , got their start on the show. As judges Katy Perry , Lionel Richie , and Luke Bryan embark on their quest to find the next big star, they are hopeful that they'll stumble upon a contestant with a future so bright they'll be able to say "we knew you when" -- and by the end of the episode, they just may have found it. Here are some highlights: Laila Mach