American Idol S05 E17 516 (The Great Idol Reunion)

"Heading back to where it all began."

"American Idol" greats -- including Ruben Studdard, Scotty McCreery, Jordin Sparks, David Cook, Lauren Alaina, Kris Allen, Maddie Poppe, Laine Hardy, Willie Spence and Caleb Lee Hutchinson -- reunite on the Idol stage.