If you’re in it to win it, you’ve probably already started working on your costume for the Utah Symphony’s 21st annual Halloween costume contest. The event takes place Tuesday, Oct. 29, at Abravanel Hall and is followed by a wickedly fun concert celebrating superheros.

Lindsey Stewart, 31, of Salt Lake City, began kicking around costume ideas for her family as soon as she got home from the event last year. She’s mum about the details, which are near completion, but her eyes are on the prize.

“We took second place in the group category two years ago,” she says. Her daughter was dressed as a bumblebee, herself as a flower and her husband as a jar of honey. Placing second is no small feat in a contest that attracts around 300 participants and has an illustrious list of past winners, including a headless Marie Antoinette, a family of sushi, a cocktail glass and a transformer robot that changes from car to helicopter.

“People go all out,” says Stewart, “that’s what makes it so fun.” She and many of her extended family go annually — they are part of symphony violinist Lynette Stewart’s brood.

Listening to their grandma play music that ranges from spooky to silly is a delight for the children. Also amusing is watching many orchestra members negotiate the music in costume during the performance.

Violinist David Langr is notorious for his get-ups, including a Star Wars’ Chewbacca costume.

“I think it’s fun for people to see Chewy playing the violin,” says Langr. When asked if he’d wear it again this year, he says he’s opting for something new. After all, there’s a prize category for orchestra members.

“Besides, it got so hot in the Chewy costume two years ago I nearly passed out,” he laughs. Trying to remedy the situation in 2012, Langr strapped a few packs of frozen veggies inside the suit.

“It worked pretty well — and by the time the concert ended, the veggies were done,” he jokes.

The contest begins at 5:30 and finishes at 6:30. Judges pick finalists who are invited onstage during the concert to be voted on by audience applause. Prizes are given to first-, second- and third-place winners in four categories: adult, child, group and symphony member.

Although most attendees don costumes, there are plenty of folks who just come to enjoy the concert. This year’s theme is “A Superhero Halloween” with guest actor Casey Elliott, who plays the role of a superhero whose identity is a mystery. The musical superpowers of conductor Vladimir Kulenovic and the orchestra help solve our hero’s identity crisis. The repertoire includes Strauss’ Also sprach Zarathustra, Elfman’s theme from The Batman Suite, Wagner’s The Ride of the Valkyries and Wiilliam’s theme from Superman.

If you go …

What: Utah Symphony's "A Superhero Halloween" concert and costume contest

When: Tuesday, Oct. 29.

Contest: 5:30-6:30 p.m.

Concert: 7 p.m.

How much: $12-$20