Once a year, James Shadd, the man in charge of keeping the 75 pianos at the University of the District of Columbia in tune, plays a concert for UDC students.

For that concert, he's not James Shadd, piano tuner, but Jimmy Shadd, jazz stylist in the tradition of the late Erroll Garner.

Shadd, the son of jazz musicians and the father of drummer (and piano tuner) Warren Shadd, said he plays for the students "so they can hear what was going on back in those days," meaning the decades that took in music-makers such as Count Basie and Fats Waller.

Shadd started out in the 1940s as a member of the U.S. Army Band and five-piece groups that played jazz dates in Washington and in New York. He still plays an occasional gig here. But piano tuning is the craft he has worked at steadily for more than 30 years, while also holding a variety of federal jobs.

It's a craft that searches for the perfect A-440 (per second) vibration but in which it's better for the tuner not to have perfect pitch, Shadd said, because a string can never be perfectly in tune. It's also a craft that requires its own tools: wrenches to tighten or loosen strings' tuning pins; "mutes" to dampen the adjacent strings while tuning; needle-tipped tools to prick and soften the hammerheads that strike the strings, creating a mellower sound; and chemicals to harden the felt-covered heads to produce more brilliance. (Washington's high humidity helps keep tuners busy, members of the profession note.)

Over the years there has been limited competition here in the business, said Shadd, who as late as the 1960s was the only black member in this area of the craft's national professional association, the Piano Technician Guild Inc.

Tuners describe Washington as a good piano town, but young people who want to go into the tuning profession say there are limited opportunities to learn the craft these days.

Shadd, 67, is one of a dwindling number of veteran technicians who takes in students. He said old-timers long ago started getting out of the business to go into radio and television work, and now, computer work.

At the same time, he maintains, young people today are impatient. "They start in it and they quit," he said. "They think they can do it in three easy lessons . . . . If you're going to become a piano technician, you have to know everything about it, because if you break a string, you've got to know how to put it back on . . . . "

Rick Butler was one young person who found himself mesmerized by the plinking and plunking of piano tuning. Twelve years ago, when a piano technician sat down at the piano in Butler's Oxon Hill home and began to fine-tune, the 21-year-old Butler was so impressed that he decided then and there that this was the profession for him.

A veteran tuner, Orman Pratt of Falls Church, discouraged him--as Butler himself has done many times since to those whose inquiries he suspects are not serious. Pratt warned Butler that it was a highly technical craft and that it would take as many as seven to eight years before he could call himself a piano technician. And, he told him firmly, it was not a get-rich-quick proposition.

Beginning tuners start at about $12,000 to $14,000 a year, but depending on skill, can rise to more than $35,000, earning more than $70 an hour in the case of concert tuners. Tuners here generally charge $30 to $50 an hour.

"But I was terribly hungry to learn," Butler said, in describing how he proceeded, undaunted, upon the long road to a top "craftsman" rating in the technician's guild, taking a course by correspondence and then serving five years as an apprentice to Pratt.

Now, as the concert-artist technician for Jordan Kitts Music Co. in College Park, Butler makes frequent professional visits to the Kennedy Center, the White House, and distinguished residences throughout the Washington and Maryland area to bring pianos into tune for such artists as Peter Nero, Leon Fleischer, Rudolf Serkin and Andre Watts.

"I'm the unseen artist," said Butler. "I work to bring the performing artist and the piano together."

Butler is one of about 40 members of the Piano Technician Guild based in suburban Maryland. At 33, he is one of the rising stars in an increasingly youthful field.

Forty-two years ago, local tuner Wendell Eaton got started in much the same way that some youngsters get into the field today: sweeping the floor in the service shop of a piano dealership. Back then, the masters tended to be elderly German technicians, who wore baggy pants and spoke heavily accented English, Eaton recalled.

In those days, he said, a tuner wasn't supposed to play the piano; the old-world piano man (not many women were in the profession then) seemed to believe that a technician with musical pretensions would tune to his own liking, and flout the trained precision that tuning demands.

Much has changed since then: the old Germans are gone, though they have passed along their precision and their pianos. And among most of those who have replaced them, there is a deep attachment to the musical artistry that they serve. Many make music themselves, including Jim Shadd and Warren Shadd--who at 26 has his own group and who just returned from London, where he played drums on the tour of singer Shirley Horn.

Twenty-four-year-old Caleb Tsai, studying in the prestigious Artist Diploma Program at Baltimore's Peabody Conservatory, has given himself until he is 30 to succeed as a concert pianist. Last year, Caleb took a step closer to that goal, winning the Peabody Concerto Competition, in which he played Rachmaninoff's Third Piano Concerto.

Last March, Caleb again found himself before a panel of judges, this time the examining board of the Piano Technician's Guild, and once more Caleb scored high, winning not only the guild's craftsman rating but the right to become an examiner himself. During the past four years, Tsai says, he has spent almost as much time improving his tuning technique as he has his performance technique, and each, he maintains, has enhanced the other.

Tsai is not unique. Though the ranks of tuners are filled with everyone from former university professors to former truck drivers, musicianship is a unifying note in the piano technician's trade. Locally, for instance, Orville Braymer of Franconia was, at 20, the youngest person ever accepted into the National Symphony when he won a seat as a trombonist in 1949.

Colette Collier, who was a professional singer, says that piano technology was the one way she knew of to stay in music and stay clear of the "backstage back-stabbing" of the professional musician.

Marshall Hawkins, a Fort Washington-based technician and vice president of the guild's southern region, swung for 23 years with the Navy "Commodores;" he was the combo's director, baritone horn player and master chief petty officer until l971.

And 30-year-old Jim Karukas of the District trades his piano-tuning services at a local studio for recording time. It's not "musician's music," he says--by which he means classical--but the tuned piano is fit for a classical concert pianist, even if it is just used for the "modern-sounding pop music" that he composes in his spare time.

The Piano Technician Guild represents about half of the 5,000 piano tuners in the U.S. and issues accreditation to those who pass its tests. Tuners don't have to belong to it, however, and one former member says he quit because he became bored with the meetings and felt they didn't advance his professional knowledge that much. "It's kind of like a club," he observed.

But as the point of contact for those looking to enter the field, the guild reports having received as many as 21 inquiries this year from aspiring piano technicians here, and tuners themselves tell of many more inquiries received in the field.

Despite what members of the profession describe as strong indications of interest among young people, area courses in piano tuning and technology are almost nonexistent, and tuners willing to assume the expense and responsibility of taking on apprentices are said to be few and dwindling.

"There's no lack of interest; there's a lack of facilities," said Wendell Eaton, himself a specialist in piano rebuilding, whose willingness to take on apprentices has provided the area with accomplished students, other tuners say.

"The best way to get into the field," said 30-year-old Collier of Silver Spring, "is to find someone who will take you on." Like many trades, piano tuning and rebuilding, the mainstays of the piano technician's craft, are learned through apprenticeship.

That means a skilled tuner takes an initiate with little more than a proven mechanical aptitude and a trainable ear, and spends time and money to teach the skills by which pianos are restored to inner harmony and outer beauty.

"Any time you talk about apprenticing with someone, you're asking that person to do a lot of giving," Collier said. Eight years ago, after taking several courses in piano technology through the Aubrey Willis Correspondence School of Piano Technology, she was taken on as an apprentice to two different technicians, Ned Dodson of Colesville and Northern Virginia's Orville Braymer.

If the experienced tuner is doing a lot of the giving, so too is the apprentice. Collier put in 18- to 20-hour days as she struggled to break into the profession. She would work all day at a piano shop and at night attend Piano Technician Guild seminars, read books on pianos, and sing professionally with the U.S. Army Bicentennial Chorus to support herself. "There are times when I'm not sure I would do it again," she said. "It was exhausting."

At Jordan Kitts, where labor problems have forced the recent shut-down of an apprentice program dating back to the l930s (no new apprentices are being taken, but those already in the program may continue), initiates are asked to work three months without pay. As trainee Karen Urssing knows, you start in the piano business at the floor level--"sweeping the floor," she said.

Kevin Kirkman, a 27-year-old trainee at Jordan Kitts, has managed to support himself--and prove his mechanical aptitude--by fixing cars when he's not chiseling bridges or finishing soundboards.

He had tried to break into the piano business for several years, thinking at the time that all there was to piano technology was tuning. At Jordan Kitts since July, he has begun to learn the piano from the inside out, and tuning is the final stage.

"It's not something you're going to get rich at," he said, but unlike the auto mechanics by which earns his daily bread, the business provides "the sense that someone is going to sit back 30, 50, maybe 100 years from now and appreciate your work."

"It gives you a lot of freedom," observed James Colwell, a Takoma Park tuner whose customers include George Washington and American universities, "although any type of free-lance work is a little seasonal. You are subject to economic pressures that people in 9-to-5 jobs just don't have."