American Idol S09 E15 915 (Class of 2006: Reunion/Idol X DWTS)

"Heading back to where it all began."

At the "American Idol" 20th high school reunion, fan-favorite idols from the class of 2006, along with special guests, return as "Dancing With the Stars" pros bring some ballroom flair to the celebration; America votes live for the Top 3.