A man dressed in a business suit leaps up and down like a Mexican jumping bean. Behind him, on a park bench, is an undulating street woman, who methodically raises her arms like the wings of a threatening hawk. Another person, dressed like a fish, slithers past them both while trains, horns and music from a park-side guitarist sound in the background.

It could be that these people are having a bad day, but actually this is a scene from a modern dance presentation about the plight of urban life.

It’s hard to know what to expect from a modern dance program, which is an aspect of the art that has probably discouraged more than a few ticket buyers. And while the the term “modern dance” defies a neat definition, almost all modern choreographers and dancers agree that untrained viewers can find something to appreciate in a modern dance piece, even if it’s just the beautiful bodies of the dancers.

“It’s a much more experimental type of dance,” says Gwyneth Jones, a modern dance instructor at Bowdoin College. “When people hear the word `ballet,’ they get a clear picture in their mind. Modern dance is not as safe an art form. You don’t know what you’re going to see.”

Jones struggles with the definition of modern dance, too. The term seems misleadingly specific for a style that has such loose boundaries and may draw from so many areas of movement including ballet, martial arts, peasant dances and tap — to name a few.

Most people think modern dance began when 19th-century American dancer Isadora Duncan kicked off her shoes, wrapped herself in a Greek tunic and began moving freely to musical rhythms.

But true roots of modern dance go back much further in history to the days before ballet slippers, toe shoes and probably footwear in general, according to Kim Arrow, dance coordinator and assistant professor of dance at the University of Maine.

“It’s a movement form that brings us back to our primal roots — when we relied more on our physicality,” says Arrow, whose own choreography and technique is influenced by East Indian temple dances.”An audience needs to understand that its a personal statement, but should approach modern dance with a curiosity and willingness to try to understand what is being communicated.”

For instance, when the business man jumps obsessively in the piece about urban life, he may be indicating frustration, especially if the music has a wild beat or the set is cluttered with trash or the lighting is a staccato flashing of lights. Or, if the man is smiling and the accompanying music is light and playful, he could be jumping for joy.

The key to arriving at an understanding of the piece is taking an impression and running with it. Being correct about an interpretation may not be as important as simply letting the mind wander with what the dancer, lighting, set, music — or the lack of any of these elements — might be suggesting.

It’s worth remembering, too, that some choreographers want to paint strange or even highly personal portraits in dance, because, they might argue, this is a part of life and art.

The danger for many pieces, however, is that they may be seen as too personal or self-indulgent. But that’s bad dance, says Arrow. If everyone is left in the dark, then the choreographer blew it.

“Dance can be communication across cultures and classes, because we’re all starting with the same vocabulary — not words but the body,” he says.

But even in these days of unpredictable art forms that continually challenge the imaginations and values of viewers, it’s likely that some will still see avant-garde dance pieces as too far out.

Because he feels that the arts are all related on some level, Arrow turns to poetry for an explanation:”Dance is like poetry. You could criticize poetry for ugly syntax, but it’s really about reading the words between the lines. It’s hard for non-dance audiences to understand dance as a means of communication, but they should try to be open to what a choreographer is saying between the lines.”

Both Arrow and Jones encourage others to attend modern dance performances with an open mind.

“See if there’s anything that makes you think,” says Jones.

Derosiers Dance Theatre, a modern dance and theater troupe from Toronto, will perform 8 p.m. Feb. 23 at the Maine Center for the Arts. For tickets, call 581-1755.