People are conditioned to make assumptions based on what they see. They see four young guys setting up to perform with mainly electric instruments, they might think they're going to hear some sub genre of rock. But by the time the local quartet Jazz Express play their last note, the audience is usually surprised - and appreciative.

"People always come up to us after gigs and say, 'Wow, we didn't know people played music like this in St. Joe," says trumpet player Tim Thomas.

Those people who haven't heard the group's jazz stylings will get a chance when Jazz Express performs at Foster's at 9 p.m. Saturday, Aug. 29.

The group came together initially in 2005 as a sextet of musicians who shared friendships and a love for one of America's original art forms.

After a few members moved away, six became four, with Thomas, drummer Chad Lippincott, bassist Andy West and guitarist Nick Grinlinton. And the group began to hit its stride.

"Whenever it became the four of us... we found our voice as a group," Thomas says.

Although some of the group's members are barely old enough to drink, they are all students of music, with West a music major at Missouri Western, Grinlinton a music major at the University of Missouri-Kansas City and Lippincott as one of Central High School's newest band directors. And Thomas thinks that each band member's musical knowledge only aids creating the genre.

"There's a lot to it. You can look at it mathematically but it's very creative," he says. "It's very left brain/right brain. You have to put the two together to make jazz."

The Jazz Express almost seems to put their shows and arrangements of familiar tunes together with an equally calculated effect. They start out playing the more laid back sounds of jazz icons like Miles Davis and John Coltrane. Then, they might switch it into a slightly different gear with some bebop from Freddie Hubbard or the jazz fusion of Chick Corea. Cut to the end of the night, after the energy has come to a boil and those few drinks you've had have started to kick in, you're hearing traces of funk from the likes of Herbie Hancock or a handful of their own original compositions, which Thomas describes as "experimental, fusion, avant garde, all wrapped into one."

"They are an energetic band. There's lots of improvising involved," says Foster's owner Nathan Karr. "It's fun to watch. They change the vibe of the room."

And after that room eventually empties out, The Jazz Express hopes the jazz - and the many forms it takes - stays with them.

"Jazz is a very, very vague word. It can describe a lot of stuff," Thomas says. "Basically, I guess my goal would be to expand the appreciation and understanding of the type of music we play around our area."