According to some soldiers' Civil War diary accounts, when their unit settled down for the evening to rest by the fire and listen to the company band, they occasionally got a response from the enemy.

"A Union band would start up and play a couple tunes, and it would waft over the hillsides and Confederate troops would hear it," said Paul Niemisto, associate professor of music at St. Olaf College, "and the Confederate band would muster up its instruments and play something back, and then the union troops would play something back again."

"It was a way of volleying back and forth and not shooting each other," said Paul Maybery, musicologist and conductor of the Yankee Brass Band.

Bands will recreate this scenario with six bands on the banks of the Cannon River during Northfield's third Vintage Band Festival. The four-day festival runs Thursday-Sunday, with more than 100 performances by local and international bands.

According to Niemisto, the festival's artistic director, in the mid-1800s, the band-instrument industry took off. "It just exploded during the Civil War," he said. "They can be heard at a distance, and they could actually help to control troop movements, not only to do inspirational marches and play for funerals, but they could actually do signaling," he said.

Niemisto, who will play euphonium with his Finnish band Boys of America, said 19th-century brass instruments are "much softer, much more mellow [and] sweet" than their modern counterparts.

Maybery compared modern brass bands to mid-19th century brass bands: "One is atomic, and the other is wood-burning."

The festival lineup ranges from Austrian or Swedish bands playing age-old scores to modern bands who relive old traditions.

Here's a sampling:

• The Kentucky Baroque Trumpets, who performed in Steven Spielberg's "Lincoln," will play 17th- and 18th-century cavalry fanfares, solos and duets on Baroque and modern trumpets.

• Kenny Carr and the Tigers, a Carolina shout band, combines gospel and News Orleans-style jazz.

• A group of eight brothers from the south side of Chicago, the Hypnotic Brass Ensemble, will play a fusion of funk, hip-hop, jazz and calypso.

• Swedish band Medevi Brunnsorkester will play marches, waltzes, polkas, opera medleys and ballads on 100-year-old brass instruments.

The idea for the festival came while Niemisto attended academic conferences in Europe and was charmed when village musicians played for foreign guests. During a similar conference in Northfield, locals decided to do the same. The response was so positive, he said, "that it began to be overwhelming. All of a sudden, we had a festival in which one of the small aspects of it was this little international conference, rather than a big conference with some music on the side."

According to festival board president Dan Bergeson, the second festival, in 2010, drew about 15,000 visitors. Bergeson anticipates even bigger crowds this year, as grants allowed organizers to bring in international performers.

During the event, the Northfield Historical Society will display vintage instruments, such as Niemisto's "helicons," pre-20th century models of marching tubas.

Many of the concerts take place in outdoor green spaces, and some local pubs host bands in the evenings. Events include a lunchtime concert and lecture series at a local restaurant, a recreation of an early 20th century vaudeville show, a vintage baseball game, a commemorative concert for local civil war veterans and a cotillion dance.

"People coming to dance can be dressed in their gussets and crinolines if they want to," Niemisto said, "or just come with their T-shirts and shorts."

Niemisto suggests bringing a bike to pedal around. Top hats and parasols also welcome.

Liz Rolfsmeier is a Twin Cities freelance writer.