What happens when Rizzo from “Grease” marries Tony from “West Side Story?” You get a modern-day von Trapp family.

Broadway veterans and married couple Matt Cavenaugh and Jenny Powers are returning to the stage — and bringing their three talented kids along for the show. Their new cabaret revue, “Keeping Up with the Cavenaughs,” hits 54 Below today, Oct. 2 and Saturday, Oct. 3. It will also be available as a livestream.

In the show, the couple and their children will belt Broadway favorites in a musical tribute to Cavenaugh and Powers’ famous past roles while showcasing their young prodigies. 

The concert marks the couple‘s 54 Below debut and the first time they will share the spotlight with all three of their children: George (14), Henry (11), and Rose (6).

“None of them has a nervous bone in their body,” Powers told The Post, noting that even though Rose hasn’t had the same theatrical training as her big brothers, she fearlessly belted out a “big solo” during her kindergarten graduation in May.

Cavenaugh is best known for starring as Tony in 2009’s Broadway revival of “West Side Story.” He has also played leading roles in “Urban Cowboy,” “Grey Gardens,” and “A Catered Affair.”

Meanwhile, Powers’s notable Broadway credits include creating the role of Meg in “Little Women” opposite Sutton Foster and starring as Rizzo in “Grease.” She’ll also be starring in the late Duncan Sheik’s final musical, “Memoirs of Amorous Gentlemen,” which opens on Oct. 15.

While 54 Below originally asked Cavenaugh and Powers to headline as a duo, Powers pitched involving the whole family after watching her husband and son Henry share the stage in a hometown production of “The Secret Garden” last year.

“We’re paying tribute to the roles that we’ve either originated or revived on Broadway,” Powers said. “We’re also singing songs that we’ll hopefully get to play someday. We’re trying to bring a lot of love and laughter — and hopefully only a little bit of family dysfunction.”

Music director Phil Reno and director Joe Langworth assembled the show. Langworth, though based in NYC, frequently travels to Arkansas to direct Link Theater productions and collaborates closely with the family.

Cavenaugh will pay tribute to his role as Tony in “West Side Story,” singing “Maria” as a trio alongside his two sons.

“Rose is trying to pay tribute to all the roles Mommy played, but let’s be honest — some of those roles are really inappropriate,” joked Powers, though Rose will be singing some “Grease” tunes… just not the ones about sex, smoking, or driving. (It will be 10 years before she can get a learner’s permit.)

Powers told The Post that for her, the show was a rare opportunity to shine as both a mother and an artist.

“I was trying to perform and still be a mom for many years while we were [in New York],” said Powers. But after the family moved to Arkansas — Cavenaugh’s home state — to raise their family, they began making their own opportunities.

In 2019, Powers and Cavenaugh created The Link, a professional theater company and educational hub in Jonesboro, forcing the couple to “root for ourselves” by recruiting former cast mates to perform while building teaching programs for kids in the arts.

Powers said the couple started their youth program because they know how impactful the arts can be, which has been evident in their children. “They learn what it’s like to step into someone else’s shoes — what it’s like to walk in their life for a day,” she said, adding that it helps instill self-confidence.

Her son George agreed. “Most kids are usually nervous talking to people, even talking to teachers, but this built my public speaking and helped me be chill like my parents.”

Which is likely why, ahead of showtime, each kid expressed excitement to The Post rather than panic.

“I’m super pumped,” George said nonchalantly.

Rose is most excited for “some friends my size” to see the show, and hints at a big duet with her mother.

His little brother Henry agreed, adding that he’s most excited for the “big stage” and a vocal battle that pits family members against each other in a note-holding battle.

“I know my parents have been stars,” said the sixth grader. “It’s time for a new generation,” Henry said.

The show will be livestreamed on 54below.org so that the Cavenaugh kids’ friends — and any other kids who aren’t allowed out past 10 pm — can livestream the show from home.