American Idol stars from past and present came out to celebrate the 20th anniversary of the show in a 1-hour episode dubbed The Great Idol Reunion, including Scotty McCreery and Lauren Alaina.

The pre-taped special, which aired on ABC on Monday night (May 2), welcomed back its original judges, Paula Abdul and Randy Jackson, and former cast members including Jordin Sparks, David Archuleta, David Cook, Justin Guarini and more.

McCreery and Alaina also made a triumphant return to the same stage that launched their illustrious careers. Offering up a once-in-a-lifetime collaboration, they entertained a crowd that included current judges Katy Perry, Luke Bryan and Lionel Richie with a touching rendition of “When You Say Nothing at All," which Keith Whitley and Alison Krauss & Union Station both made famous.

McCreery began the ballad by showcasing his powerful, baritone vocals reminiscent of Josh Turner’s on the first verse. He then was joined by Alaina, who stepped out wearing a ruffled, off-the-shoulder top and a pair of sparkly pants. Alaina poured all of her emotion into the second verse before the two singers joined their voices together in beautiful harmony.

“That was just amazing, guys,” Bryan raved afterward. “We’re all touring so much, us country people, we can’t ever get to see each other sing. I was just like enthralled, a fan, just sitting back and listening. It was really good to hear you all.”

McCreery and Alaina have come a long way since experiencing separate runs on Season 10’s American Idol. McCreery won the tenth season, while Alaina was the runner-up. At the time, both artists were teenagers.

Now, 11 years later, McCreery has notched four consecutive No. 1 hits with “Five More Minutes,” “This Is It,” “In Between” and “You Time.” Alaina, meanwhile, scored two No. 1 hits with her song, “Road Less Traveled,” and the duet “What Ifs” with Kane Brown.

Other collaborations that were featured during the two-hour reunion special included Ruben Studdard and Jordin Sparks, Maddie Poppe and Caleb Lee Hutchinson, Willie Spence and Grace Kinstler and Kris Allen and David Cook.

American Idol returns Sundays and Mondays on ABC.

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What happened to some of country music's best American Idol contestants over the last 20 years? This list of country American Idol stars who disappeared includes a winner, a runner-up and a third place finisher, plus several early cuts who enjoyed radio success before losing touch with fans.

PICTURES: See Inside Carrie Underwood's Beautiful Post-'American Idol' Home

Carrie Underwood invested her money wisely after winning American Idol in 2005. One of her first big purchases was a 3,099-square-foot home in the well-to-do Nashville suburb of Franklin, Tenn. Underwood paid $384,000 for a luxurious 3-bedroom, 3.5-bathroom stone and stucco home in a private gated community.

The house features a library, a vaulted ceiling and lovely amenities throughout, but while it's very nice, it's certainly not the kind of home you'd picture for a budding country superstar. Underwood wound up being a huge success right out of the gate with her debut album, Some Hearts, and she sold the home in Franklin for $372,500 in 2007, when she purchased the Brentwood mansion that she would later share with her husband, Mike Fisher.

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