Metro

This NYC high school for the stars is full of cutthroat divas

Ruby Karp has a talent manager, has hosted regular stand-up shows since she was 11, published her first book (“Earth Hates Me: True Confessions from a Teenage Girl”) last fall, been a Dove spokesperson and even given a Ted Talk on feminism. But for the life of her, the 12th-grader can’t do one thing: land a role in her school musical.

To be fair, LaGuardia is no ordinary high school.

Better known as the “Fame” school, thanks to the 1980 film and TV show, the Upper West Side performing arts institution has launched a boatload of stars over the years, including Jennifer Aniston, Liza Minnelli, Al Pacino, Sarah Paulson and 2018 Oscar nominee Timothée Chalamet. Admission is so competitive, it’s an honor to just get in. But that’s never enough for budding thespians.

So when it’s time to try out for the annual play or musical, diva behavior and neuroses take center stage.

Ruby KarpMindy Tucker

Some 350 to 500 students, out of 3,000, are said to audition each spring for 35 or so coveted spots in the next school year’s productions. Tryouts recently wrapped for December’s “The Sound of Music.”

“Competition is fierce. There are many talented performers, and precious few roles — just like the real world,” says drama teacher Harry Shifman, a mentor of Chalamet’s.

Agents and other entertainment-industry players often attend the shows to scout for Hollywood and Broadway talent — in fact, actress and rapper Azealia Banks was discovered this way.

For Upper West Sider Ruby, being in the school musical “was the dream.” But she’s been shut out for three years, despite having hired a $180-an-hour vocal coach. Last year — her final shot — she got “30 seconds” for her audition. “I didn’t even get a callback,” Ruby, 17, said. “I was devastated.” (She went on to write about the rejection in her book.)

While roles typically go to rising seniors, some favorites are reportedly groomed as underclassmen.

“It’s a Hollywood system within a small pond,” said Ruby’s mom, Marcelle Karp. “Some teachers could give a s–t about the rest of the kids when they’ve already found [one] they want to support.”

But once you’re in, you’re golden.

“If you get a lead in the musical, everybody looks at you like [you’re] royalty,” Ruby added, noting that four of her friends signed with an agent after the annual show.

Yael Rizowy, class of 2011, felt like Cinderella at the ball once she landed the lead in “Hairspray” her senior year — opposite future Hollywood star Ansel Elgort. The two ended up going to prom together.

Yael Rizowy in front of LaGuardia High SchoolTamara Beckwith/NY Post

“The popular girls started talking to me,” said the 25-year-old, who now lives downtown and is an actor/writer.

At the same time, her best friend stopped speaking to her after the pal was cut from auditions.

“It’s just jealousy, and at such a young age you don’t really know how to handle it,” said Rizowy, adding that the competition leads to “low blows and broken friendships.”

Some of the low blows even come from administrators.

On the day of her audition, Rizowy was shamed by a teacher for noshing on French fries. “He said, ‘You’re eating this?!’ ” she recalled.

John Walsh, now 23, starred in the school’s 2011 production of “Guys and Dolls.” He, too, felt pressure from instructors when one encouraged him to get an acting coach over the summer.

“It was almost like you have a job after school,” he said of rehearsals that can last until 8 p.m. on weekdays and also stretch over weekends. After all that, Walsh — who now lives on Staten Island and works as a production assistant — came down with pneumonia a week before the show.

“It was the talk of the school,” he said, adding that the sharks immediately started to circle. “My understudy would have loved [for me to drop out], but I wasn’t giving him that chance.”