'American Idol' Ends Tonight With Its 15th and Final Season

— -- THIS ... is the end of "American Idol."

Tonight's two-hour finale will feature a parade of winners, past contestants and judges, all coming together to bid goodbye to a TV show that changed the pop culture landscape -- and the music business -- forever.

As judge Harry Connick Jr. put it, "It's designed as a search for a musical pop superstar, and that's exactly what it's done."

"It’s supplied the pop music world with gigantic stars," he told ABC News. "I think the statistics with regards to record sales and awards are just mind-boggling."

Reigning champ Nick Fradiani, who'll give up his crown to either La'Porsha Renae or Trent Harmon tonight, agrees.

"It’s amazing to me to think that a show has been that successful for 15 years.... I mean, it’s just unheard of," he told ABC News. "'Idol' changed music and pop culture forever.... I mean, to think of the amount of awards these artists have won ... 'Idol'’s been the only show that has figured out how to propel artists into fame and into real success."

"In a climate ... when there’s just a ton of noise and it’s really hard to cut through, to have a show like that, that gave people who otherwise might not have had the opportunity a chance to be heard, I think is awesome," added season 7 champ David Cook.

"It kinda shaped some music for a little bit?" said season 8 champ Kris Allen. "Kelly, Carrie -- those people wouldn’t have happened without the show. Can you imagine country music without Carrie Underwood? I can’t. Can you imagine pop music without Kelly Clarkson? I literally can’t do it."

But "Idol"'s ability to create stars isn't the only thing that made the show special.

"I think the biggest thing that separates 'American Idol' is it kinda brought families together. It was something that you’d go to work the next day and everyone was talking about it," said season 5 finalist Chris Daughtry.

"It just felt like a very community-based show.... I think this one certainly will leave that legacy behind," added Daughtry, who said he's "eternally grateful" for what "Idol" has done for him. "I think that’s a big, big thing that that accomplished: bringing people together."

In addition to Cook, Allen, Daughtry, Fradiani, Underwood and Clarkson, all the other "Idol" winners will be present and accounted for tonight: Fantasia, Taylor Hicks, Candice Glover, Ruben Studdard, Lee DeWyze, Scotty McCreery, Phillip Phillips and Caleb Johnson.

In addition, many runner-ups and fan favorites will appear, including Kimberly Locke, Katharine McPhee, Kellie Pickler, Elliott Yamin, Justin Guarini, Sanjaya, Melinda Doolittle, Allison Iraheta, Clay Aiken, Constantine Maroulis, Bo Bice, Blake Lewis and -- if rumors prove true -- William Hung.

So dim the lights, Kieran ... it's time for one more "Moment Like This."