his city of 35,000 is not normally regarded as a by-station on the international music circuit. But yesterday, Barry Tuckwell, the most famous of French horn virtuosos, announced that he will form a symphony orchestra for Hagerstown and become its music director.

The ensemble will be called the Maryland Symphony Orchestra, will consist of a core group of about 50 musicians and will play six programs a year in the handsome Maryland Theatre, a recently restored movie house of 1915 vintage. The first concert is set for Nov. 13.

Citing earlier efforts to form volunteeer orchestras here, Tuckwell said that this one would be "professional," in the sense that all musicians would play under contract and would be bound by its terms.

The Australian-born Tuckwell, who tours as a horn soloist on four or five continents every year, said he plans to make western Maryland his base for the roughly six months that he spends in the U.S. each year. At a press conference he anticipated the obvious question: Why?

"I suppose I could answer, 'Why not?' " he said, "but that isn't really an answer."

Tuckwell said he formed an attachment to this area--about 90 miles west of Washington--after years of coming here to have his horns repaired at the Boonesboro workshop of Walter Lawson, "who makes the most marvelous French horns." Another factor was that Tuckwell clearly is eager to get back into some orchestral music after a 13-year solo French horn career that has equaled both in celebrity and monetary success that of any other classical solo brass player.

Yesterday, the mustachioed and goateed Tuckwell, dapper in a gray double-breasted suit, recalled his years as first horn of the London Symphony Orchestra; for several years he also served as the head of that player-run ensemble. He cited that experience as a precedent for his interest in building an orchestra from scratch in western Maryland. "When we started out in the LSO it was not that good," he said, "and by the time I left it had become what it is today. The new orchestra will consist of players from this region, both from Hagerstown and from the four states that converge in this area." Asked if professionals would be imported from the larger cities, Tuckwell said he was against "mercenaries."

He made a fervent statement about the need for a conductor who is a part of community. "I have strong views about absentee conductors. They are the ones who drop in from time to time when it suits them. That will have to be the case here the first year, but not afterward."

Tuckwell's home is in London, in a six-floor house overlooking Regent's Park where he lives with his wife, Hilary, and his son, Tom. He also is music director of the Tasmanian Symphony Orchestra in Australia. In addition, he is guest-conducting this year in Houston, Winnipeg and Toronto.