“American Idol” celebrated its 20th birthday in style Monday night.

The show marked the milestone with “The Great Idol Reunion”, which saw past “Idol” contestants and judges return to the stage.

Ryan Seacrest even revisited his frosted tips at one point, as well as welcoming iconic season 3 contestant William Hung to the stage to sing the Ricky Martin hit “She Bangs”.

WILLIAM HUNG on “American Idol”. Credit: ABC/Christopher Willard
WILLIAM HUNG on “American Idol”. Credit: ABC/Christopher Willard

“You know, it really is great to look back and celebrate all that’s gone on in this very studio over the past 20 years. I can’t help but feel that someone is missing the party,” Seacrest teased before the performance.

READ MORE: Christian Guardino Impresses ‘American Idol’ Judges With His ‘Best Performance Yet’ As He Belts Out ‘The Lion King’ Classic

He added, “Someone who helped put this show on the map, dare I say, the legend, whose very name is synonymous with ‘American Idol’.”

Former judges Paula Abdul and Randy Jackson also returned to appear alongside current judges Katy Perry, Luke Bryan and Lionel Richie.

READ MORE: HunterGirl Slows Things Down For An ‘Inspiring’ Cover Of ‘Tangled’ Anthem On ‘American Idol’

“I am most proud, most humbled by having the experience of a lifetime,” Abdul gushed, according to Variety. “And being able to see it continue to grow and do well and see — I’m crying seeing all of the contestants who are like my babies.”

“We see all this talent out here,” Jackson shared. “We did something right.”

The show also featured duets with season 6 winner Jordin Sparks and season 2 winner Ruben Studdard and season 10 winner and runner-up Scotty McCreery and Lauren Alaina, as well as an appearance from season 1 runner-up Justin Guarini.

David Archuleta surprised those viral crying girls, as well.