MARIETTA — Children shouting happily or singing mightily provided the soundtrack to the city of Marietta’s Santa on the Square annual Christmas tree lighting ceremony Thursday night.

The Square was host to about 200 visitors at 5 p.m., when Walker Lower School students took the stage as the first of nine musical acts.

“I get to hear my sister sing,” 7-year-old Elizabeth Matthews of Marietta said about West Side Elementary School student Anna Matthews, one of the school’s Singing Stingers.

More than 2,000 residents were expected to participate in the event at some time during its three-hour duration, according to city Parks and Recreation Director Rich Buss.

On a clear night with temperatures hovering at 60 degrees, family groups met, mingled and navigated strollers through the Square’s lanes and lawns.

Children sat on shoulders, clambered over walls or stood on benches, the better to see over a sea of bright red hats with snow-white trim, cookie-colored sweatshirts and tree-green jackets.

First-time attendee Shari Murray of Marietta brought her daughters in hopes of starting a family tradition.

“It’s the first Christmas she’s been active,” she said about her 17-month-old daughter Tiffany as they posed for cellphone photos by the 30-foot Leyland Cyprus from 7 G’s Christmas Tree Farm in Nicholson.

It sported the colors of North Pole ice floes, decorated by parks department Recreation Supervisor Maggie Moss.

Fellow employee Jerry Smith had his hand on the secret switch illuminating the park at exactly 6 p.m., following a countdown by Mayor Steve Tumlin and his granddaughters, Alli Patrick, 6, and Rhodes Patrick, 4.

“They have practiced for two weeks,” Tumlin said. “They’ve been looking forward to it all year.”

It was all Elizabeth wanted, according to her mother, Susan Matthews.

“She loves the lights,” Matthews said. “It’s all she’s asked for this year — to see Christmas lights.”

Children ready to ask Santa for their hearts’ desire waited on the park’s playground.

“I want Ariel,” Grace Maier, 4, waiting with her grandmother Inga Maier, said about a doll based on Disney’s “The Little Mermaid.”

“We love Christmas,” Maier said.

James Lowe, 4, son of Tarver Lowe of Marietta, said he wrote a letter to Santa.

“I’m so excited,” he said about his visit with St. Nick, as he waited with neighbor Dawson Roper, also 4.

Excitement reached a fever pitch when sirens signaled the arrival of the fire engine carrying Santa and Mrs. Claus, a cue that sent children rushing for the park’s perimeter.

The police escort helped Santa’s ride, an antique 1949 Pirsch ladder truck, circle the park, after which the celebrity couple made their way to the pavilion.

First in a 50-family line was Caelen Towe, 8, a student at Bells Ferry Elementary School.

“Get here early,” he advised next year’s crop of petitioners.

His classmate, Joshua Newton, also 8, discussed a page-long document with Santa.

“It was my list,” he said about requests for books, games and a trampoline. “He said, ‘Have you been a good boy this year?’ I said, ‘Yes.’”

Also good were 6-year-old twins Lizann and Maddie Brown, daughters of Carla Brown of Mableton, who came to hear their friends from Marietta First Baptist Church sing, 8-year-old Gavin Beatty of Canton who said it was exciting to celebrate Christ’s birthday, and 8-year-old Matthew McKenzie.

“I really like the tree,” said Matthew, who attended with his brother Donovan, 10, and their mother Monique McKenzie of Marietta. “It’s actually the biggest tree I’ve ever seen.”

Tumlin said the long-running event is a big part of the season.

“It gives us a good Christmas spirit,” he said. “This park was made for this.”