FREEPORT — Heather Petrie said she was more nervous when she sang at Mast Landing School than she is to sing at the Metropolitan Opera.

Petrie, who graduated from Freeport High School in 2001, will be performing in Ludwig van Beethoven’s only opera, “Fidelio,” next month at the Met in New York City. The show runs from March 16-April 8.

Petrie, 34, is a contralto singer, or “lady bass,” as she calls herself. Her interest in singing began at Mast Landing School, where, she said, auditioning for the school chorus “seemed so scary.”

Although she did well over the years and was accepted into Maine’s district and state choirs, Petrie said her nerves didn’t subside until the last year or two of high school.

“I eventually pulled myself together and stopped being so nervous,” she said.

Petrie said she had to remain calm if she wanted to be successful.

“I started carving out this path of being a professional choral singer,” she said.

Auditioning for a chorus always requires singing a solo piece, which is what Petrie said makes her the most nervous. Nerves lead to a shaky singing voice, though, which then leads to losing work.

To combat her fear, Petrie said she had to switch her perspective and think of each audition and performance as exciting opportunities, rather than chances to fail. That mindset is what took Petrie from performing in summer shows with the Freeport Players to being nominated for Grammy awards and singing at the Met.

After earning her bachelor’s degree in voice from Bard College and her master’s degree in opera from the State University of New York at Purchase, Petrie found work as a choral singer in New York City. She said she’s always preferred singing in a chorus, and not just because it’s less nerve-wracking.

“When I’m singing a solo it’s just my voice,” Petrie said. “There’s just one part happening. With a chorus, I get to add my part to the tapestry of other voices. It’s bigger than just me.”

The singer said she felt pressure in college and graduate school to be a solo artist, or a “diva,” but didn’t want to betray her true passion for singing with groups.

“When you’re solo, the focus is on the singer,” she said. “But in a group, the focus is on the music.”

Petrie makes a living singing for various choruses, and has made a few CDs with the group Etherea. She’s also in Clarion Chorus, which was nominated for a Grammy this year in the Best Choral Performance category.

Petrie first auditioned to be in the Metropolitan Opera in 2010, and, after her fourth audition, she was accepted. She said she received the phone call last March informing her that she had been chosen to be in the extra chorus for “Fidelio.”

“I tried to play it cool when I was on the phone, but once I hung up I started jumping up and down,” she said.

The extra chorus consists of 30-40 singers, and Petrie said she one day hopes to be chosen for the full chorus.

Petrie said she feels confident in her ability, which she credits to her time singing and performing in Freeport.

“I think one of the most important parts of the music and theater scene in Freeport is that it was taken seriously,” she said. “We were held to a higher standard than one would expect from a tiny high school.”

Petrie, who no longer has family in Freeport, said she likes to visit when she can, but finds it difficult with her schedule. She said she’s excited by the arts scene in town, especially the Freeport Performing Arts Center, which was built two years after she graduated.

“I thought we were good when we were performing in the cafeteria with no air conditioning,” she said.

Petrie said she reflects on her start in Freeport fondly and hopes other Freeport students realize they can follow their dreams as well.

“My biggest advice is to be self-motivated and pursue your interests because you never know where they’ll lead you,” she said.

Kate Gardner can be reached at 781-3661 ext. 125 or kgardner@theforecaster.net. Follow her on Twitter: @katevgardner.

Freeport High School alumna Heather Petrie took this selfie to celebrate her upcoming performances at the Metropolitan Opera in New York City.

Heather Petrie graduated from Freeport High School in 2001. She’ll perform at the Metropolitan Opera March 16 to April 8.