As the joke falls flatter than a Marine sergeant's crewcut, the front row squirms. It's so quiet, one could hear a career drop.

Welcome to stand-up comedy open mic. It's a twisted two-plus hours of hit-and-miss humor that tends to separate future comedy stars from those whose act could be loosely translated to "don't quit your day job."

While sometimes agony for unsuspecting audience members, open mic nights also bond neophyte comics honing skills with the dream of becoming the next Dave Chapelle.

Open mic is the comedian's internship. It's a minor leaguer's long bus trip. And they've all been there. The Pryors. The Carlins. Robin and Lily. And the new hot guys like Dane Cook and Brian Regan.

They have to start somewhere. And this is where. And that's just fine with Julie Anderson, a transplant from the frigid tundra of Duluth, Minn., where it's so cold, the Ice Age would be considered a heat wave.

Quite simply, "comics need stage time," said Anderson, who visits the hat rack Tuesday nights with duo duties as stand-up comic and producer of "World Comedy Jam" at Listen & Be Heard, a downtown delight for local denizens and up-and-coming performers.

"I love Vallejo," said Anderson. "And I love this cafe. It's like someone pulled it out of Haight-Ashbury in 1972 and dropped it in Vallejo."

Anderson, 39, always wanted to roll the dice and try her luck at comedy. Growing up "in a poor white neighborhood," she took her Christmas money and bought Pryor and Steve Martin albums. The chance just never presented itself until Anderson left Duluth, where the temperature could plummet to 100 degrees below zero.

"Sometimes, it would be too cold to snow," Anderson said. "It was just bitter, bitter cold."

When the window of opportunity presented itself, Anderson escaped.

"I saved my money from working at McDonald's and left when I was 18," Anderson said. "I wasn't my choice to be born there. It was my choice to get out."

After a few years in Minneapolis, Anderson headed West. She lived in L.A., then Seattle and, about 15 years ago, Napa. For reasons she couldn't explain, she put comedy into second gear and enrolled in San Francisco Comedy College, a sort of Camp Yuks with joke coaching and act analysis.

The college, though without an athletic department, "could still beat the 49ers," Anderson quipped, adding seriously, "It was a really great place for comics."

Anderson found her personality meshing with others hoping for the road warrior lifestyle.

"Comics are a bunch of crazy people," she said. "We're sharing our neurosis on stage."

Unfortunately, in an era that's a an eon from the comedy boom of the 1980s, open mic nights are gallons of gas between each other. So Anderson talked to Listen & Be Heard co-owner Tony Mims. And "World Comedy Jam" was a done deal with Anderson and Jorge Castaneda co-hosting three Tuesday nights every month after the improv group, Rats in the Alley, kick-off each month's first Tuesday.

Don't look for Anderson to dazzle the crowd for an hour.

"I'm still fairly new at this," she said. "I know my limitations."

This last Tuesday, the comedy show attracted about 25 people, including nine comics of varying ability and experience led by veteran Kenny Yun.

"I try to keep the line-up diverse," Anderson said. "A lot of times what you get (in other venues) is the all white boys comedy show."

And, she added, there won't likely ever be on rookies or an entire show of veterans.

"I want it to be a good blend," Anderson said.

It's all about the close-knit comedy family, be it performer or fan.

"Networking in the community is a really great thing," Anderson said. "San Francisco and Boston are two for the best cities to start in comedy. They're really receptive."

It's great, Anderson said, watching a new comic evolve.

"If they're having a hard time, the audience feels it too," she said. "It can be painful. I've had many painful experiences. But that's what it's all about. It's the experience. People can see comedy's not easy. But then you can see someone six months later and they're a completely different person."

Anderson realizes the comfort zone at Listen & Be Heard could be an uncomfortable zone somewhere else. But it's part of the job.

"Again, it's the stage time," she said. "I've got people coming from the Southbay. That's how valuable stage time is. It's about exposing yourself to different audiences. If you play the same room every week, it gets old. People are like, 'I've heard that joke a million times.'"

Back home in Duluth a now-divorced mom and dad somehow handle their daughter's career path.

"They seem to be fairly entertained by the fact I'm doing it," Anderson said. "I don't think they've ever heard me as happy as I am right now. We'll see if they ever get a chance to see me do this and whether they feel the same way."

Though the "World Comedy Jam" is an informal night out for five bucks, Anderson takes her job as promoter seriously.

"I got an e-mail from a comic, 'I have car problems,'" Anderson said. "I e-mailed back, 'It's important you're here. This other guy's coming from The City."

The comic in alleged distress got a ride to Vallejo.

"Don't try to weasel on me," Anderson said smiling. "So far, people have been great. Everyone's fired up to go."

And if a joke takes a dive faster than a bribed boxer, so be it.

"You never find one comic who will make everyone laugh," Anderson said.