Getty American Idol's May 4 episode will give fans a flashback to 2006! The ABC singing competition series is giving season five's contestants a 20-year anniversary reunion, bringing back five former contestants for special appearances alongside the Top 5 of the current season. For those who don't remember, season five actually gave us several major stars. The winner that year was Taylor Hicks, but the runner-up was Katharine McPhee, who went on to be a big star on TV with shows like Scorpion and Smash, as well as Broadway with multiple runs in the musical Waitress.