In the musical "family" of Ruben Zavenovich Vartanyan, who conducts the Arlington Symphony Orchestra, conversations are carried out with gestures, not words.

But as exuberant as some conductors can be with their body language, Vartanyan tries to be "reasonably modest" in his mien. A lift of the eyebrow, a tilt of the finger is good enough for him.

Perhaps it befits the Moscow-born Vartanyan that he did not want anyone accompanying him to his naturalization ceremony June 3, coincidentally his 63rd birthday. "I do so think this a very private ceremony," said the Ballston resident, who has no relatives in the United States.

In interviews, orchestra board members and others say that, during his seven years as conductor, Vartanyan has made what was a competent orchestra sparkle. "It's well beyond what it used to be as a community orchestra," said Sen. Mary Margaret Whipple (D-Arlington), who presented Vartanyan with an American flag at an orchestra fund-raiser last month.

Bonnie Williams, the orchestra's executive director from 1991 to 1997, said that when Vartanyan was a guest conductor during the 1991 season, "everyone knew he was the best conductor any one of us had seen."

Although the orchestra by many accounts is among the lowest-paying professional ensembles in the area, local musicians such as Sarah Wetherbee put aside their initial reservations to play with it.

That is partly because Vartanyan does not always choose music that everyone knows, said Wetherbee, 30, a freelance violist and violinist who has played under the late Leonard Bernstein and many conductors in the region.

But more importantly, she said, "He puts the music ahead of himself. . . . I decided I didn't care if it didn't pay as much money. I really enjoy playing with Ruben."

The son of a clarinetist and a pianist, Vartanyan spent his youth around classical music. At age 3, his parents took him to the opera "Faust," and except for a brief time in his late teens when he considered a career in math and physics, he knew he would dedicate his life to music. "It is impossible to serve two masters," he said. "You must be educated absolutely" in one subject.

After graduate studies, he persuaded the esteemed Herbert von Karajan, conductor of the Vienna State Opera and Philharmonic Orchestra, to be his mentor for a year. From von Karajan, Vartanyan learned discipline. Every day, he spends up to 14 hours poring over scores, rethinking previous interpretations of a work.

That practice sustained him during the late 1970s, when he could not find work because his private, anti-Soviet views had leaked out. He was hardly a political lion, he said. Still, it took four years to persuade the authorities to let him conduct again.

After he was a guest conductor of "Carmen" at the Bolshoi Opera in 1979, he spent the next nine years there, one of several conductors with the 900-member organization.

After his wife, Tatiana, died in 1986, Vartanyan knew it would be only a matter of time before he would find the right moment to defect. One night in Bolivia, where he was conducting the Bolshoi, "I just disappeared," Vartanyan said. He had sympathetic friends in that South American country because he had conducted its national symphony during the late 1960s.

Vartanyan surfaced in Arlington, where he said he knows many people, including Mstislav Rostropovich, the former music director of the National Symphony Orchestra. Vartanyan taught privately and at area colleges until he was hired by the Arlington Symphony in 1992. In 1993, he also became music director of the 36-piece Williamsburg Symphonia.

This fall, Vartanyan is planning something he has not done in his years with the Arlington Symphony Orchestra--repeating a work. In this case, it is one of the first pieces he conducted with the ensemble, Tchaikovsky's Symphony No. 4. By press and other accounts, that original performance was sterling, with a Washington Post reviewer writing that "virtually everything could be heard as if framed in gold."

"I'm very curious to make the comparison," Vartanyan said, downplaying the old kudos. "I assure you, it will play as if it's another orchestra."

CAPTION: Ruben Zavenovich Vartanyan, a Moscow native who became a U.S. citizen earlier this month, has been the conductor of the Arlington Symphony Orchestra since 1992.