Miles Hoffman has grown quite fond of two little asterisks -- the ones that precede his name on the list of National Symphony Orchestra musicians in the Kennedy Center's Stagebill.

A name preceded by just one asterisk (*Miles Hoffman) would merely be a "Regularly Engaged Extra Musician." That would make Hoffman a regularly engaged extra violist. But, two asterisks (**Miles Hoffman) translate into a season's "Leave of Absence" for the orchestra member.

Next year when the asterisks are redistributed, however, Hoffman's name won't be on the list. After seven years with the National Symphony Orchestra and one year's leave of absence, he has resigned. The 33-year-old violist, who has been critically acknowledged as "a confident instrumentalist with a suave tone," is turning his full attention to chamber music and solo performances.

"Those asterisks didn't come cheaply," the tall, lanky violist says, half in jest and half as a sobering gesture of confession. Loosely estimated, an NSO musician earns $40,000 a year, and when asked if he cut his income by half to go on leave, Hoffman answers with an exaggerated, "Oh yeah!"

"But it is so clearly the right decision," he says, "that there is no point in being nervous. It's really not a confusing decision . . . Playing in an orchestra was never my goal. It was something that fit the moment . . . I'm glad I did it, and I'm glad I've left when I have."

One of Hoffman's chief chamber music commitments is the Library of Congress Summer Chamber Festival, which he founded in 1982 and which begins its annual offering of five free concerts tomorrow night at 8 in the Coolidge Auditorium. Hoffman's activities with the Summer Chamber Festival have also evolved into a new chamber music ensemble -- the American Chamber Players -- which keeps him busy both as a violist and as a manager.

As Hoffman talks about the decision to strike out own his own, Moose, his cat, pads quietly around his duplex apartment in Adams-Morgan. A viola-shaped pillow with a sadly wobbling neck shares the sofa with his real instrument. Hoffman reaches for a paperback book -- a biography of Nietzsche.

"I was just reading this last night," he says. And quoting from the introduction, he offers a description that corresponds to his situation: "It is not merely that he was never satisfied with what he was. His anxiety was that he would dwindle, become less than he was, if he was not becoming more."

Later he draws from the aphoristic wisdom of the Talmud: "If not now, when."

For Hoffman, it comes down to a belief that the orchestra is not particularly conducive to artistic self-regeneration. "An orchestra player," he says, "is a cog in a wheel. It's a very lovely wheel, but you are still a cog . . . If individual creativity and responsibility for and determination of your own choices is important to you, then an orchestra is not the place for those forms of expression."

In a symphony orchestra, decisions are not made by the musician but by the conductor and the artistic director. "You don't even decide when to pick up your instrument and put it down," Hoffman says. "A conductor says, 'Start at letter A,' and you pick up your instrument. If he stops and rehearses the clarinets for five minutes you have your instrument on your lap, and then he says, 'Start at letter B,' you have to pick it up again."

But chamber music, he explains, is the definitive collegial relationship. "You discuss things. You choose together. You have individual responsibility that becomes shared responsibility. And choices are made in consultation with your colleagues and friends."

Five hours of orchestra rehearsal are much more tiring, Hoffman says, than five hours of chamber music rehearsal. "It's because of passivity and the lack of individual responsibility. People look at the clock in orchestra rehearsals. It never occurs to me to look at the clock in a chamber music rehearsal."