One night in April, after Maria D’Amato performed in the comic opera “L’Elisir d’Amore,” she had to push past groupies, who were waiting by the stage door of the Metropolitan Opera.

This month alone, she’s in Mozart’s “Don Giovanni” and “Die Zauberflöte” (“The Magic Flute"), Verdi’s “Aida” and Wagner’s “Der Fliegende Holländer” (“The Flying Dutchman”). But the fans were not camped out by an underground parking garage to see D’Amato.

“It was like I was invisible,” she said, days later, while chatting backstage at the Met Opera. “They only had eyes for the stars.”

D’Amato is many things: a mother, wife, chorister and a world-class soprano. But a star? No.

She does not have more than a million followers on Instagram like, say, Aida Garifullina. Nor has she been the focus of a BBC documentary, like Cecilia Bartoli.

Once, a fan mistook D’Amato for one of the star vocalists. When she explained that she was actually Maria D’Amato, a chorister, they “just dropped me right there.”

“From far away, you know, makeup and wigs, we all kind of look similar, I guess,” she said.

Maria D’Amato, a chorister for the Met Opera, does her makeup for a stage dress rehearsal of Don Giovanni.

D’Amato has a sly smile when she recalls her brush-offs, because she’s in on the joke: In New York City, you can have a contract at the Met, do 175 performances a season and be ignored even by opera buffs.

But her anonymity is part of the job. As a chorister, D’Amato is supposed to take her highly trained soprano, which she has spent decades cultivating, and disappear into the chorus, melding with her colleagues into one voice.

Choristers are “kind of like unsung heroes,” D’Amato told me by the stage door. “The orchestra, they’re amazing musicians. But so are we.”

Met Opera choristers, including D'Amato (third from right) surround Ying Fang, playing Zerlina, in a rehearsal of "Don Giovanni."

On a Wednesday last month, D’Amato had a busy but typical workday. It spanned 13 hours, with three operas in two languages. She had rehearsals for “Don Giovanni,” which opened Friday, and for “Die Zauberflöte,” which opens May 19. Then, at 8 p.m. she performed alongside 27-year-old hotshot tenor Xabier Anduaga in “L’Elisir d’Amore,” which closed April 29.

D’Amato has been doing a version of this schedule for more than a decade.

Act 1: “A perfect chorister”

Behind the scenes, the Met Opera is a labyrinth of subterranean rehearsal rooms. It feels like an enormous, underground public high school – complete with a cafeteria, locker rooms, warning bells and announcements about who’s called to the stage.

There are groups divided by voices: tenors, basses, altos and sopranos. There are strong friendships, as well as tensions – the logical outcome of having so many divas spend so much time together in tight spaces.

It’s like a “functional and dysfunctional family,” said D’Amato.

The chorus meets to rehearse “Die Zauberflöte” (“The Magic Flute").

Throughout the building, one can hear TVs blasting what sounds like an opera CD – rehearsals being streamed so the cast and crew can track what’s happening onstage.

The Met Opera's chorus master, Donald Palumbo, whom everyone addresses as “Maestro,” said D’Amato “possesses everything you need to be a perfect chorister.” She can “produce full sound, yet maintain the purity of the tone and the beauty of the tone.”

D'Amato at rehearsal.

He says he began trying to recruit D’Amato around when he started at the Met Opera in the 2007-08 season, but she wasn’t done with her solo career. Although choristers can audition for some designated solos, the leads are commonly imported from outside the Met Opera.

By 2012, however, D’Amato was starting to think about starting a family, and it seemed hard to schlep those theoretical children to Airbnbs, or leave them for a few months while she chased gigs in Sarasota or Charlottesville.

“I knew that if I kept saying no, there’s a whole line of people that want this job,” said D’Amato.

D'Amato retreats backstage between rehearsals.

And checks in with her family.

Act 2: “Wheels on the Bus”

Where else is an opera singer with 20-plus years of experience going to find a steady gig, with summers off, and a pension, in New York City? D’Amato says it’s the kind of job people keep until they retire.

And she has tried other jobs: She taught singing and also sang in a church choir.

“I did everything,” she said. “I cleaned, I babysat, I did anything to piece together a career.”

Two years ago, when theaters went dark, she even taught a baby music class.

“I obviously don't use my opera voice,” she said, noting that she dialed down the vibrato before singing classics like “Wheels on the Bus” and “Open Shut Them.”

She thought about pursuing baby music full time. But then theaters reopened and opera lured her back, as it always has.

D’Amato didn’t get into opera for money or fame. She fell in love with it when she was 15 and saw a performance of “La Bohème” at the New York City Opera. The music made her cry.

“I loved everything about it,” she said. “I liked how the music made me feel, that it made me feel emotion, and feel sad and sympathetic towards the characters. I liked that feeling.”

Many roads in D'Amato's life lead to “La Bohème.” As a first grader, she watched it on PBS with her mom. It’s D’Amato’s favorite opera, and it’s also how she met her husband, an opera singer, during a reading of the libretto when they were in a production in Sarasota.

Act 3: Sacrifice

“As wonderful as this job is — and it is, it’s an amazing job — it’s also just an incredible sacrifice of time and coordination,” said D’Amato’s colleague and locker room neighbor, Christina Thomson Anderson, a mezzo-soprano who has been a Met Opera chorister for more than a decade.

Thomson Anderson said her husband, who is also a professional opera singer, “really didn’t get” how much work it was until he himself joined the Met Opera, years after she did.

“It was like this light bulb went off,” she said. “Like, this is a lot. It's great, but it's a lot.”

For starters, there’s the schedule. Choristers can work Christmas Eve, New Year’s Eve and weekends, in-season. They work long days. There are physical demands: costumes and corsets can be heavy, and sometimes performers stand or kneel for hours in shoes they wouldn’t choose.

Once, when D’Amato was nine months pregnant, she had a solo in “Turandot.” She had to climb up a ladder onto a platform, which was then raised about 20 feet above the stage, where she sang.

“That was insane,” she said, looking back. But that memory fills her with pride, even if her feet were so swollen from all the weight and standing that she took pictures of them.

“Even though this job is crazy and so busy, I still get to go home every night and I get to be with my family,” she said. “Even if it’s just to kiss them goodnight, and say, well, mommy’s gotta go again.”

D'Amato heads home to have dinner with her husband, Dimitrie, and their two children, Natalie and Matteo. Her break is only an hour, before she returns to the the theater for an evening performance.

Act 4: Goodnight

On a recent Wednesday, after a full day of rehearsals, she stopped home to see her two young children: 14-month-old Matteo and Natalie, who just turned 5.

Her husband, Dimitrie Lazich, whom everyone calls “Dimi,” had a pasta sausage bake waiting on the table.

“You need to eat and drink before seeing an opera,” he said, offering wine, which D’Amato refused because she didn’t want to fall asleep.

Lazich performed at the Met Opera earlier this year in “Lohengrin.” During the play’s two intermissions, he and D'Amato had date nights in the cafeteria.

“That’s the only time we could be alone,” he said.

That night, D’Amato was home for 44 minutes — just enough to eat, see her kids and change her shoes before heading back for “L’Elisir d’Amore.”

D'Amato and Natalie look through a photo album.

When she arrived at the Met Opera, people were milling about on the Lincoln Center plaza, waiting for friends or dates. Some women wore fancy ball gowns, complete with ruffles and shimmery heels. There was a low-level buzz in the air, the excitement before a big night out.

D’Amato says she sometimes forces herself to walk through the front door of the opera house, to remember that there is magic to her workplace.

“Just because it's the hundredth time we've sung a piece, or even more, it's the first time for somebody else,” she said.

She then disappeared backstage.

The new production of “Don Giovanni” is on at the Metropolitan Opera through June 2. It is also transmitted live on May 20, at movie theaters across the city and the country.