It's difficult to feel jaded when you're in a candlelit crowd of thousands singing "Silent Night."

That's just what happens each year at Wolf Trap during the annual Holiday Sing-A-Long that in recent years has hosted about 7,000 participants at the free event. Guests are urged to vocally join in as the United States Marine Band and a choir of roughly 400 vocalists from top local and regional groups leads the audience in singing traditional holiday songs. The evening ends with the rendition of "Silent Night" and a candlelit procession out of the Filene Center.

"The Sing-a-Long is one of the first things I saw at Wolf Trap 17 years ago," said Terrence D. Jones, president and CEO of Wolf Trap. "To me, it is one of the things that make Wolf Trap unique. When you have 7,000 people gathered for this occasion in the spirit of giving and generosity, it creates a very vivid memory that has never left me."

Catherine Filene Shouse, Wolf Trap's founder, began the tradition in 1968 by inviting local church choirs to her home to join in carols and holiday cheer. Although Shouse died in 1994, the tradition has grown even stronger with an array of volunteer singers and hosts at the event.

2012 Holiday Sing-A-Long
Where: The Filene Center at Wolf Trap, 1551 Wolf Trap Road, Vienna
When: 4 to 5:30 p.m. Saturday
Info: Free, no ticket required. Attendees are invited to bring a candle, bells and a new, unwrapped gift for the Toys for Tots drive; 877-WOLFTRAP (965-3872);

One of the volunteer hosts is Danielle Rohar, a Falls Church resident, who takes special delight in watching the all-ages-crowd take the printed lyrics and sing along.

"It's just a very special event," she said with a laugh, noting that many members also bring bells to ring during the special "Jing-A-Long" during the performance of "Jingle Bells." "It's fun to see all of the people really enjoying the songs and the evening."

Vanessa Caceres, who now lives in Bradenton, Fla., with her young son, fondly remembers seasons past when she and her family would join in the spirited holiday fun.

"The Holiday Sing-A-Long is a terrific event," said Caceres, who lived in the D.C. area until a few years ago. "When I had a child myself, I really understood what a great tradition it has become for so many families."

An added bonus at the event is that participants are invited to bring new, unwrapped toys to leave at the Toys for Tots collection. Attendance is free though, and a toy is not required for admission.

"You know what I love about it," said Jones. "It's cross-generational. You see families of four generations together, singing the great songs of the season and having a great time. It really does appeal to everyone."