Here's Everything We Know About the Guest Mentors on Season 21 of 'American Idol'

More than two decades after American Idol made its debut on network television, the series still has the country in a chokehold. The 21st installment of the wildly popular ABC reality singing competition series kicked off in February, introducing viewers to the latest group of vocalists vying for the $250,000 cash prize.

The series sees their talents put to the ultimate test. Luckily, they have a few celebrity guest mentors to help them out along the way. In the past, contestants have been coached by industry legends like Mariah Carey, Diana Ross, and Kenny Rogers.

So, who are the coaches on Season 21 of American Idol? Read on to find out!

If the coaches on this season of American Idol look familiar, it’s because they are.

Season 21 of American Idol featured a blast from the past. Along with Season 1 runner-up Justin Guarini, a few other familiar faces returned to the show for Hollywood Week – including but not limited to Clay Aiken, Jordin Sparks, and David Archuleta.

Additionally, Phillip Phillips from Season 11, Catie Turner from Season 16, and Season 20’s Noah Thompson served as mentors for the Season 21 hopefuls.

As of Sunday, April 16, only 26 contestants remain in the competition, and the stakes are high. With little time left until the Season 21 finale, American Idol producers recently called in celebrity reinforcements.

Guest mentors Allen Stone and Noah Cyrus joined the cast and crew of American Idol at Disney's Aulani Resort in Hawaii to offer a few words of advice to the Final 26.

With more than 800,000 monthly listeners on Spotify, Allen knows a thing or two about reeling in an audience. The self-described “hippie” gained popularity online following the release of his self-titled album in 2011. In the years that followed, he made appearances on Conan and Ellen Degeneres.

Last year, Allen competed in NBC’s American Song Contest with his original single “Bit of Both.” In the end, didn’t take home the win. He did, however, place in the top five.

Noah, on the other hand, pretty much grew up on TV. Thanks to her father, Billy Ray Cyrus, and her sister, Miley Cyrus, she’s lived most of her life in the spotlight. At the 63rd Annual Grammy Awards, Noah was nominated for Best New Artist, though, she ultimately lost to Megan thee Stallion.

Tune into American Idol Sundays (and some Mondays) at 8 p.m. ET on ABC!