Randy Fisher is a blithe, bearded 32-year-old viola player with the Omaha Symphony and has lately become anxious about the tempo of the arms race. It started when he heard Roger Molander, founder of "Ground Zero," on Larry King's late-night radio talk show and decided he had to get involved.

Last Friday night, Fisher more or less presided over a planning session of the Omaha branch of Ground Zero, an organization that encourages improvisation in its 650 chapters. People are running, dancing and picnicking against nuclear war. Omaha's organizational meeting may have been the only one to open with Mozart.

Fisher explained to the 17 thirtyish people who to his astonishment turned up in the neutral decor of a room in the University of Nebraska-Omaha Religious Center, "I thought we would have a little Mozart to relax us all before I laid this heavy load on you. You can browse through this material while we play."

He distributed Roger Molander's book, "Nuclear War: What's in It for You?" and also Ground Zero newsletters and a map of Omaha with varicolored concentric circles indicating the damage the city would suffer if the Soviets dropped a one-megaton bomb on nearby Offutt Air Force Base, headquarters of the Strategic Air Command.

Then he and Tracy Dunn launched into a Mozart duet for viola and violin, while members of the group leaned back and drank in the lovely, twining sounds. They played selections from Bach, Bartok and Sir Thomas Morley and returned to Mozart for the allegro vivace finale.

"If Mozart could speak the way he wrote music," Fisher said reverently, "he should be addressing this group."

Fisher came to Omaha only last September but has already learned one thing: "Almost from the first syllable, you alienate people around here."

What he meant, of course, is that Omaha's conservative nature, which prevents it from tackling doomsday issues it feels are the province of military and government, is deepened by its loyalty to SAC, which both protects the area and puts it high on any presumed missile targeting list.

Omaha seems to be no more ambivalent about SAC than it is about Boys Town, its other claim to fame.

Offutt employs 10,000 people and, according to Col. Mike McRoney, SAC's director of public affairs, "We have an awful lot of interface with the community."

Even the sight on a CBS defense documentary of the simulated incineration of Omaha, fireball and all, did not cause any lasting second thoughts.

Says Archbishop Daniel Sheehan, who supports the nuclear freeze: "It disturbed people for about a day. It is hard to say that SAC's deterrence hasn't been successful over the past 30 years. It has been an extremely good neighbor, and the program did not provoke a single call to force the base out of the community."

At the religious center, the Ground Zero band considered the basic hopelessness of persuading the locals that they could trust the Soviets. Omaha is not alone in believing that the treacherous Soviets would somehow circumvent verification. The suspicion has been identified by Molander as the next great obstacle.

Fisher ruefully reported the failure of earlier organizing efforts. "Everyone went off to join the freeze. It's sexier, I guess. Our job is educational, telling people what nuclear war would be like," he said.

Someone mentioned that Billy Graham was working for both the freeze and Ground Zero.

"Now you've alienated me," one young man said sardonically.

Fisher said his request to set up tables at shopping malls had been turned down. The merchants said it would be bad for business.

A husky, dark-haired man named Harold Bauer who, like most of the group, works at Boys Town, kept offering a Ground Zero slide show. He reported an unlucky recruiting strike. He had approached a colleague who turned out to be a former SAC intelligence officer, who said when asked to join Ground Zero, "I'd like to nuke them til they glow."

Finally, after more meandering discussion, the group reluctantly agreed to watch the slides.

Bauer read from the script: "Americans go about their daily lives despite the threat: a mother and child in a supermarket." But on the wall flashed a frame of an elderly couple. Several people began to chuckle. Bauer tried again, for Americans going about their daily lives. A picture of Gerald Ford and Japan's Emperor Hirohito in the Rose Garden appeared, and the room exploded in laughter.

By the time Bauer got the slides in sequence and showed the last scene of Hiroshima after the blast, people were still wiping tears from their eyes.

"We've laughed together as a group, and that's important," a pretty young woman from Boys Town assured Fisher.

The group decided to meet in two weeks.

It was a beautiful, aimless, funny evening, and it wouldn't cause a quiver in the military-industrial complex if it weren't happening in many places. With or without Mozart, the nuclear debate has begun.