By late 1943, World War II was raging.

Americans were falling on faraway battlefields, while those at home worked in factories and kept their ears to the radio.

"In that era during the war, life was so depressing that music, movies and big bands were their salvation," said Erin Reilly, 28.

Reilly and Matthew Decker, 26, both King of Prussia natives steeped in theater, have researched the songs, swing dances and spirit of the 1940s.

All are revisited in

Holiday Show at the Swing Club

, a new musical to be staged by Theatre Horizon from Tuesday to Dec. 31 at the Montgomery County Cultural Center in Norristown.

Decker directs the show; Reilly acts in it. Both created the nonprofit Theatre Horizon in 2005.

The 80-minute show is being performed in a theater that has been entirely transformed into a 1940s nightclub.

The action unfolds on New Year's Eve 1943, as a bandleader gathers fellow musicians and singers for one last show before heading to war and the characters must face life without him.

"It's not at all like a play," Decker said. "The performers are constantly talking to the audience, emulating what it would have been like to be there at a swing club on New Year's 1943."

It would have been lively, Decker said. The show features swing and tap-dance routines. There is vaudeville-style comedy. And there are familiar jazz numbers, such as

It Don't Mean a Thing if it Ain't Got That Swing.

To be convincing, the half-dozen actors had to roll back their cultural mindset.

"This character [the band leader] has not experienced rock-and-roll, the sexual revolution or Britney Spears," Reilly said.

"Sexuality was so different. The banter between men and women was more veiled. It's very beguiling to see what we've totally lost, because now, we're all out there."

Perhaps the biggest challenge was grasping the humor of the era, Decker said.

"The comedy was all puns and wordplay and rhythm and slapstick back then," Decker said. "Now, we rely on the easy laugh."

In October, the pair visited the Kennett Area Senior Center in Kennett Square for hints of what life was like during World War II. Center members, teenagers at the time, told of sacrifices everyone made for the war effort.

But those were balanced by "a sense of overwhelming optimism that we were going to win the war," Decker said.

Asked what members would have done on New Year's Eve 1943, one said: "Be around people I love and listen to the radio."

That gave Reilly and Decker the platform they needed to shape the show - music.

"We let the music inform our voices, our bodies, our attitude," Reilly said. "We use the music as a doorway to the past, to encapsulate it."

Decker said period costumes, a certain performance style and altered speech patterns also helped the pair recreate the 1940s.

Reilly plays a cocktail waitress whose future is marred by the bandleader's leaving. But she adjusts and learns to "step out on her own," the actress said.

"That mirrors the role of women of the day, who gained a sense of strength and independence," Decker said.

Decker graduated from Upper Merion High School in 1999 and from New York University, where he studied theater. He trained as an actor, but found he preferred directing.

Reilly graduated from Upper Merion High in 1997 and majored in theater, French and anthropology at the University of Pennsylvania. After graduation, she and Decker decided to form Theatre Horizon, making drama their full-time job.

Theatre Horizon does not have a building, but relies on community theaters for a stage, the two said.

Its $130,000 budget this year comes from government grants, foundation gifts, private and corporate donations and ticket sales. Ticket sales cover about half the cost of producing a show.

Holiday Show at the Swing Club

grew out of Reilly's vow to entertain families during the 2007 holidays. It also is intended to pay tribute to those who lived through the 1940s.

"In another 10 years we won't have these people, and it's receding into the past," she said of the swing culture.

"Jazz music was an original American art form and an antidote to Nazism."

If You Go

Holiday Show at the Swing Club

runs from Tuesday to Dec. 31 at the Montgomery County Cultural Center, 208 DeKalb St., Norristown.

The performance will be in the fourth-floor Centre Theater. Show times vary, and tickets range from $15 to $25. Reservations are suggested. For more information, call 610-283-2230 or visit

» READ MORE: www.theatrehorizon.org

.

Contact staff writer Bonnie L. Cook at 610-313-8232 or bcook@phillynews.com.