He's a traveling repairman in the universal uniform -- plain navy blue work shirt and pants. The results of his labor are more often heard than seen, tested under vaulted ceilings and marble arches, bounced off mosaic murals, the object of his loving attention something that "can be a whisper or a roar."

He's Bob Wyant, pipe-organ man.

Five days a week, Monday through Friday, he works for Newcomer Organ Co. on upper 18th Street NW in Mount Pleasant, sometimes at the company's workshop filled with tall pipes and sugar-pine wood in Smithsburg, Md., and sometimes on the road, headed for cathedrals or village churches, "barnstorming" the rural areas with a helper, trying to reach as many as he can.

Weekends, Wyant is the main organist at his own parish in Arlington, the Cathedral of St. Thomas More, where he plays for two Sunday masses and, occasionally, weddings and funerals.

"My mechanical bent is stronger than the musical; there's a bit of an imbalance there," he allows. "I have occasionally toyed with taking on a more full-time church job, but I've always stayed with the way I've always done it."

He's done it this way since 1948, the year he joined Newcomer Co. and landed the job of assistant organist at the Franciscan Monastery in Northeast Washington, the two careers developing simultaneously, he says.

"When you both play and work" on organs, says Wyant, "you really have an in-depth knowledge of what's happening and why it's happening." Of just over two dozen pipe-organ technicians in the metropolitan area, about two-thirds are also musicians and about half of those play for churches. "After you tune it, you try it," he said. Often, he plays hymns, sometimes from a hymnal left open on the console by the regular organist.

Usually, Wyant knows the hymnbook's owner, either through membership in the American Guild of Organists or through Newcomer Co., whose seven technicians service 141 organs in the Washington area, mainly for churches and a few universities, dividing most of the local market with two other pipe-organ repair companies, Lewis and Hitchcock Inc., and Irving Lawless Associates.

Wyant is familiar with all 141 organs. Fixing four organs a month, he's not on the road as much as he once was, when a typically active month involved about 24 trips, usually for routine tuning and common problems such as water damage from a leaky roof.

Now, Wyant spends much of the week in the Mount Pleasant office, assigning work crews and drawing up proposals for repairs or modifications, with the company averaging 18 jobs a week. Most of the work is done on a contract basis for clients paying between $200 and several thousand dollars annually, depending on the size and complexity of their instruments and special needs.

Sensitive to weather changes, even the simpler or smaller organs should be tuned twice a season, when the heat comes on and goes off, for instance, and more complex ones may need monthly attention. The unseasonably cool days at the end of summer meant some organs were "behaving as if it were fall," says Wyant, who tried not to send crews to those instruments to avoid "false tuning."

Once in a while, a dream of a job comes along such as the rebuilding of Washington Cathedral's organ, a task that took 3 1/2 years, between 1973 and 1977. Wyant was the foreman on that project, which resulted in an instrument experts consider exceptional. There was a "great deal of artistic satisfaction in that," he says, not only with the "intellectual part" but also "just the experience of doing things with my hands."

The job involved expansion, renovation and redesign--pipes were added, parts were replaced, and the tone was modified to produce a clear bright sound more suited to the works of Bach and other classical composers. The organ "was kept usable in portions all through the project but it was very exciting when some new sets of pipes were installed" and played "to hear the sound as it actually came to life," Wyant says.

In a church with fine or "live" acoustics, like the cathedral, the note reverberates through the room and "the music just takes on a certain sheen," he says. Discovering those is one of his pleasures in going from church to church.

In such a place, the sound seems especially "timeless," and Wyant is reminded that his craft goes back more than 1,000 years, when organ pipes were "very much the same" as they are today.

More times than not over the years, Wyant has played to an empty church. The atmosphere is one he loves, because the job "gives you a chance to get away from the hustle-bustle" outside and into another world. For the organ man, there's just one word to describe it: "serene."