Hollywood Week has arrived on “American Idol,” which marks its 20th year on air this season. For that reason, several familiar faces are returning to the show tonight as mentors during Hollywood Week.

Among the “Idol” alums reporting for duty on tonight’s episode, which was filmed in December, are: Season 7 winner David Cook, Season 10 runner-up Lauren Alaina, Season 2 winner Ruben Studdard, Season 9 winner Lee DeWyze, Season 10 second runner-up Haley Reinhart and Season 19 champ Chayce Beckham.

“I always enjoy those opportunities,” says Cook, who mentored in the past on the show’s pre-ABC days and is always willing to assist up and coming artists. “It’s such a unique experience to go through. And maybe I can help some of these kids navigate it a little easier.”

While in the past the show featured appearances by Carrie Underwood and Adam Lambert, this move marks the first time since “Idol” rebooted on ABC in 2018 that former Idols are being brought back “help the new class,” longtime executive producer and showrunner Megan Michaels Wolflick tells Variety.

“It’s like a sorority-fraternity, big brother-little sister kind of thing,” she explains. “It’s really cool because they’ve been through the process and they understand Hollywood Week. A lot of them had their own iconic moments during Hollywood Week.”

“We’re a big community, a big family,” adds Alaina. “We all have this understanding of one another, because it is such a unique experience, and it is so life-changing. I think we all have a great appreciation for each other.”

Alaina, who auditioned for the show 11 years ago — and has since parlayed that experience into a career that includes appearances on “Dancing with The Stars,” the CBS show “Beyond the Edge,” Hallmark movies, an induction into the Grand Ole Opry and a current tour — says she was willing to help because, “I have literally been in their shoes [and] I know how overwhelming it is.”

“Fish out of water is the best way to describe it because no matter how experienced you are as a singer or a vocalist or a performer,” the country singer continues. “If you’ve never been on live television like that before, it’s such a wild and amazing experience. It’s so nerve-wracking, even for people like me, I felt really proud to be able to go back and give them some comfort more than advice. I told them every emotion that you’ll feel is valid. It is crazy, but it is so life changing.”

Wolflick says that bringing the alumni back as mentors to assist during one of the most intense weeks of the competition is a way to help the current class move ahead. Viewers already got a taste of this with former Idols like Season 11 winner Philip Phillips, Season 19 runner-up Willie Geist, Alaina zooming in to offer encouragement to contestants. Even Season 4 top 8 alum Nadia Turner returning (to her own surprise) to watch daughter, Zareh, audition and earn a Golden ticket to Hollywood.

“Who better to work with them than someone who’s been there before who understands what it takes to get through Hollywood Week?” says Wolflick, who came on board with the show in 2003 for Season 2. “Every one of them leapt on the opportunity and was an absolute yes, right away. They were so excited about it. Everyone came with bells on, they wanted to do more. What else can we do? They were all so excited to be back and to meet these contestants.”

For some former Idols — like Studdard — returning was surreal. “For Ruben, who was on ‘American Idol in 2003, he’s working with contestants who weren’t even born then. This was a full-circle, crazy moment to kind of give back to the next generation.”

So how is this going to work? Wolflick explains that each Idol will mentor in perspective categories — pop, rock, R&B and soul. For example: Studdard will work with the R&B contestants, Cook will work with the rockers, Sparks mentors the pop category, Alaina with country, Reinhart will work the soul category, while Beckham will offer advice and talk about his recent experience as an Idol winner.

Wolflick says each mentor brought something different to the table. “Ruben was very honed in on song, choice and delivery, whereas Lauren was focused on working with some of the younger contestants. She could say I was 16 when I was on this show. So I understand how you feel.”

Adds Cook: “I got to talk with them as a group, and then I broke off with maybe five or six of them to work with them through their songs. Anybody who’s watched the process, even on TV, you can tell there’s a lot of talent in the room and I think the people that can differentiate themselves are typically the ones that can hone that talent into creating a moment in their performances. You only have a minute or two to sway a judge or to get somebody’s attention. It’s imperative that you take those opportunities when they come up.”

In addition to advising contestants to find “moments in their songs” to accentuate, Cook — who has released multiple albums, starred in Kinky Boots on Broadway and recently released his second EP, “The Looking Glass” — was also laser-focused on the mental health of the hopefuls.

“Hollywood Week, especially, is a lot of work and not a lot of sleep,” Cook says. “Everybody goes into it all excited, [and] by the end of the week, everybody’s so frazzled. That’s when you start to see the tears and the meltdowns and all that. So, I was trying to help them navigate that too– the mental, psychological aspect of just how crazy Hollywood Week can be.”

Cook also tried to work with the talent on their live performance, as some had limited experience outside of small gigs and social media.

“I tried to be of service, pointing out, ‘You’ve got the talent to do this, and I understand the cameras and the lights and all of that could be very distracting, particularly if you’re not used to performing live in those settings with no net,'” he says. “‘You’re here for a reason, so just be confident in your space and let all the other stuff that’s going on around you go.  It’s all peripheral. It’s all noise. As a performer, it is your job and your responsibility to own that space.'”

And what of the cardinal sin of Hollywood Week — forgetting the lyrics?

“Having been on the other side of it, I can empathize with the lyric thing,” says Cook with a laugh. “It’s not always the easiest. I know Archie (runner-up David Archuleta) and I both messed up lyrics at one point or another, and I know there were others throughout our season, but I think I was fortunate enough to have had experience forgetting lyrics in the past and figuring out a way to kind fake your way through it.”

Offers Alaina: “The great thing about ‘Idol’ is it gives you pretty instant fame, but it doesn’t necessarily give you instant success. Success has to be earned. You have to work for it. I’ve been working for everything I have for 11 years. I tried not to overwhelm them because this is so early on, but I did try to tell them like, this is just the beginning, do your job here — and then your career starts after. … I wouldn’t have the things I have without Idol and the hard work. It takes both.”