Idina Menzel, Kristin Chenoweth & More Give Us the Scoop on 'A Very Wicked Halloween' (VIDEO)

Meaghan Darwish
Preview Virginia Sherwood/NBC

NBC is celebrating one of Broadway's longest running shows this month with A Very Wicked Halloween: Celebrating 15 Years on Broadway.

Wicked's original stars, Idina Menzel and Kristin Chenoweth, are set to reunite once more to honor the occasion with a concert event. Additionally, the concert event will see the Broadway heavyweights joined on stage by Ariana Grande, Adam Lambert, Pentatonix, and Ledisi.

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Plus, all of those buzzed-about themed episodes.

Ahead of the October 29 special, TV Insider spoke with Menzel, Chenoweth, Lambert, Pentatonix, and Ledisi about what viewers should expect.

"It feels terrific," Menzel gushed about reuniting with Chenoweth. "It’s very special, I think that it’s important in life to have moments when you’re forced to reminisce and reflect on something very remarkable in your life because we’re always moving so fast and it’s hard to stay in the moment."

A VERY WICKED HALLOWEEN: CELEBRATING 15 YEARS ON BROADWAY -- Pictured: (l-r) Kristin Chenoweth, Idina Menzel -- (Photo by: Eric Liebowitz/NBC)

The Broadway superstar has become a pop cultural icon for her role as Elsa in the 2013 film Frozen, but her heart will always be with this show. "I find it very emotional and moving to be here side by side with [Kristin] and do this special," she continued.

Chenoweth, like Menzel, has made a name for herself outside of Broadway with TV and film roles, including recent gigs on NBC's Trial & ErrorMom, and American Gods. She offered similar gratitude for the opportunity, saying, "I can’t wait for [fans] to see a little time capsule. And it’s gonna be on film for my family and people that I know and love for all these years to see and I’m just proud of that. So I hope they enjoy us enjoying it."

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When the musical debuted in 2003 on Broadway, Chenoweth and Menzel took on the lead roles of Glinda and Elphaba — otherwise known as the "Good" and "Bad" witches of the Oz made famous by Dorothy and her friends.

While Menzel and Chenoweth didn't discuss their actual performances too much, NBC did release two sneak peeks of the two singing their respective songs "Defying Gravity" and "Popular."

Meanwhile, talk of a movie adaptation had both singing a similar tune. "There better be," Chenoweth began, joking that she could be involved but it "depends on how big the camera lens is." Menzel echoed her friend's tune, quipping, "I think with the green makeup and some CGI, I would look amazing."

Both of the stars are involved in philanthropy when they aren't performing — Chenoweth's Broadway Bootcamp in Oklahoma is "a week of intensive singing, acting and dancing and it’s not for the faint of heart." She added, "But it will bond you. Some of the kids I’ve watched over five years are still best friends. And that’s to me what it’s about, I love it, I’m so proud of it."

Menzel, on the other hand, launched the A BroaderWay Foundation in 2010 which is dedicated to offering a creative outlet for girls in underserved communities.

These two weren't the only ones feeling nostalgic at the event. American Idol alum Adam Lambert also shared his surprising connection to the musical, which made his participation in the special all the more special.

"I understudied the part in the fist national tour and in the LA company," he revealed. "It’s nostalgic having a rehearsal this morning with the original musical director who directed us when we all learned it for the first time years ago. It’s just so crazy."

A VERY WICKED HALLOWEEN: CELEBRATING 15 YEARS ON BROADWAY -- Pictured: (l-r) Ledisi, Adam Lambert -- (Photo by: Virginia Sherwood/NBC)

Lambert will be performing alongside Ledisi, who revealed the reason she's excited to be a part of the event. "I’m able to express myself in another outlet that most people don’t know about me is my love for theater, so I’m excited about it," she said.

Kirstin Maldonado and Mitch Grassi of Pentatonix, on the other hand, were just major Wicked fans. "We’ve ruined our Wicked CDs by playing it so much, it just felt so great," Maldonado detailed of being invited to perform. Grassi then teased, "We get to sing with the orchestra too which is amazing cause they’re so good."

A VERY WICKED HALLOWEEN: CELEBRATING 15 YEARS ON BROADWAY -- Pictured: Pentatonix -- (Photo by: Eric Liebowitz/NBC)

So how does a musical like Wicked remain relevant? Lambert pointed out how, even after 15 years, it's still "really relatable."

"I mean, everyone can kind of see themselves in one of these characters and the themes that the show brings to the table are really important and layered," he said.

Menzel added, "I think even the Glindas can identify with Elphaba because we all have that thing inside of us — that doubt and that insecurity, that feeling of not belonging, being misunderstood, and wanting to be accepted for who we are. I always feel that way even now, and I’m just lucky I get to sing her songs all of the time and remind myself to like, get it together."

Fans can sing along when the special airs Halloween week on NBC.

A Very Wicked Halloween: Celebrating 15 Years on Broadway, Monday, October 29, 10/9c, NBC

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