A venerable holiday tradition had a local sound this year as the Trumbull High School Honors Chamber Choir took the stage at Radio City Music Hall to open the annual Christmas Spectacular.

The show has run at Radio City every year since 1933.

“It was an unforgettable experience,” said Trumbull High junior Caroline Marchetti. “Performing on that iconic stage was a dream come true. I am truly grateful I got to do it.”

The Trumbull singers perform in various venues each year. Still, the sight from the stage of the 5,900-seat venue, with its triple-decked balcony, was awe-inspiring, Marchetti said.

“It was incredible and an honor,” she said.

Before the show began, the choir knew it was in for something unique, said choir director Anne Tornillo. The audience at the Saturday matinee began applauding as the choir warmed up backstage. The applause continued after the final strains of the Pentatonix version of “Oh Come, All Ye Faithful” stopped echoing through the hall, she said.

Following the performance, the choir members took their seats to watch the rest of the show.

Though the THS part of the performance was only about five minutes, Tornillo said it was technically demanding.

“There were 13 different parts, featuring 30 singers,” she said. In addition to singing, various choir members provided what professionals call “human percussion” or beatboxing, she said.

The Radio City performance originated earlier this year, when the show’s management reached out to Tornillo to ask her to submit audition materials. The choir has a reputation for delivering solid performances, having performed in Lincoln Center and Carnegie Hall in prior years.

“They know our kids are going to be well-prepared, and they can augment the choirs, so we continue to be recommended,” Tornillo said.

Still, the Radio City show was different, Tornillo said.

“It’s a giant stage, and thousands of people,” she said. “When the lights come on and the curtain goes up, it’s a real thrill.”

The Trumbull High Chamber Choir is an honors-level performance class. Each year, Tornillo said 50-60 singers, most of them already accomplished performers with the school’s concert choir, audition for about 13 open spots.

“The kids auditioning are already part of the school’s freshman choir or full concert choir,” she said. “They’re all very good singers.”

Once they are accepted into the Chamber Choir, there is a rigorous rehearsal and performance schedule.

“We push them hard, and they perform all over,” Tornilllo said.

But Tornillo said all the hard work pays off in the end.

“Many of my former students have gone on to become music teachers,” she said. “Many others remain connected to music in their later careers. My joy is knowing they’re cultivating their love of music.”