Before candle-toting carolers fill Jackson Square for the French Quarter’s annual Christmastime singalong on Sunday, a rising star with New Orleans roots will perform at St. Louis Cathedral to help begin the festive evening.

The singer David Castillo, a graduate of Jesuit High School and Loyola University, performed for national audiences on the most recent season of NBC’s “America’s Got Talent” with the “boy band” opera quartet Vox. On Sunday, he’ll perform for his hometown during the annual Christmas concert at St. Louis Cathedral. Castillo and other soloists will join the cathedral’s concert choir and orchestra in performing works by J.S. Bach and Randol Alan Bass under the direction of Dreux Montegut.

The concert is free and starts at 5:30 p.m. as prelude to the Caroling in Jackson Square gathering, scheduled to start at 7 p.m.

Other soloists at Sunday’s cathedral concert include soprano Angela Mannino, mezzo-soprano Claire Shackleton, tenor Dana Wilson and bass Horace English. Like Castillo, they all have strong New Orleans connections.

The concert is a double homecoming for Castillo, both to New Orleans and the cathedral. His singing career began as a youngster in the cathedral’s Boychoir. His later professional credits include performances at Los Angeles’ Walt Disney Concert Hall and the Mahalia Jackson Theatre with the New Orleans Opera. Most recently, it included a role in “Hopscotch,” an avant-garde opera by multiple composers and directed by Yuval Sharon. The piece was performed in 24 limousines rolling through the streets of downtown Los Angeles.

Castillo’s legit career took a left turn this year for Vox’s short run on “America’s Got Talent.” Though the group was eliminated from the competition, the national TV exposure it offered has opened doors for him and his fellow singers.

Concert appearances by Vox — presented on the NBC talent show as a young, hipper Three Tenors (Plus One) opera act — are planned next year in California and Canada, and the group is exploring recording opportunities.

“We’ve been courted by some managers ever since ‘America’s Got Talent,’” Castillo said. “And we’re trying to figure out the best journey for the group. We’ve all learned so much about the business. For me, I definitely have learned a lot for my own personal business.”

That has recently included exploring a side career as an actor. Since “America’s Got Talent,” Castillo has been taking acting classes and going on auditions, and he’s recently landed representation with Anthony Laciura’s manager. Laciura is the New Orleans native and Metropolitan Opera veteran who played Nucky Thompson’s valet Eddie Kessler on the HBO series “Boardwalk Empire.”

“Since ‘America’s Got Talent,’ people have been saying I have a good look for TV, and I’m just trying to capitalize on it right now,” Castillo said. “It’s been a really beautiful year, learning about how to take that next step for everything in all parts of life right now. I love opera. I’ve got a great career going. It’s also nice these other options have just appeared.”

Montegut, Castillo’s director in Boychoir and voice teacher during high school, said, “David’s done very well.”

“He’s one of our prized students,” he continued. “He’s gone off and done very nicely.”

And Sunday he returns to help give voice to Bach and Bass.

Castillo said his personal connection to the cathedral makes the engagement special.

“I’m very grateful that Dreux thought of me to be a soloist at a place where I grew up singing,” he said. “It’s so beautiful, especially during Christmas.”

“People will be coming down to the French Quarter on that particular day, for Caroling in Jackson Square and all of the things going on,” Montegut added.

“It’s really a special time.”