"If you are going to win, you've got to keep from falling into the competition trap."

So said 31-year-old Arthur Greene yesterday, just hours after he took first place in the 16th annual University of Maryland piano contest -- now named the William Kapell Competition -- following a commanding performance at the Kennedy Center Saturday night of the thorny, exhausting Brahms B-flat Concerto with the National Symphony under Julius Rudel.

*Greene, who was trained at Yale and Juilliard, emerged the winner after 10 days of intense contention among 35 contestants who were chosen from more than 90 young pianists applying to enter. This year the festival was directed for the first time by the eminent pianist Eugene Istomin as part of a concentrated effort to upgrade its importance in the musical world.

In such a competition, Greene said with assurance, you sweat it out just as much as is suggested in the classic stereotypes of such events.

"What I mean by the competition trap," he said, "is fretting about what the judges may think, what other people think, and so on. The only way out of it is to focus on the music, and try to exclude everything else."

A bearded, stocky man with intense eyes and enormous hands, Greene has learned this lesson from hard experience, and some disappointments. He started out seven or eight years ago as a competition whiz. Early on, he won two competitions easily.

"I hought I was invincible," he said.

Then, in 1983, he entered the Maryland competition for the first time and did not win. He was a semifinalist. "I wasted too much of my energy worrying," he said. "I would hear some little remark that would bother me, and it would set me off."

Also, he feels that he played at considerably less than his best. "My big piece then was Brahms' 'Handel Variations.' I mutilated the piece by leaving out some of the repeats in order to squeeze it into a given time."

One of the biggest changes in Greene's life since, he said, is improved control over his "attitude." If he had any strategy to win, this was it. And, he commented, "I can't imagine myself in a much more stressful situation than the Kapell competition . But I guess that's going to be the case as long as I am playing the piano . . .

"Now I do meditation and I find it very helpful. I play regularly in Japan, and I became fascinated by Zen. It helps keep the mind more centered and relaxed."

On the day he won, Greene spent hours meditating. "I touched the keyboard only at rehearsal. I actually sat alone here in the office of Istomin's wife Marta, artistic director of the Kennedy Center and went over in my mind the Brahms B-flat, over and over. All I was thinking about was the piece. That way you don't have any wrong notes."

This was a break from Greene's norm, for he tends to practice from dawn to dusk, with a pause in late afternoon to jog, "so that it divides the day in half." He is also strict about his diet. "I haven't eaten any sugar for a long time. And I haven't eaten any red meat during this competition."

Sufficient sleep, however, is another thing. He got only two hours on the night after his victory.

Greene started work on the Brahms B-flat Concerto, which is the longest one in the standard repertory, about three years ago. "It is very difficult, but it just draws you," he explained. "It is so rich and deep on so many different levels."

He did not study the interpretations of a wide variety of players. "But I always find it helpful to listen to Rubinstein," whom Greene never heard in concert. "It is the way he sort of lives his conception. He never lets himself get in the way of the music."

Does he imitate Rubinstein?

"Oh, no. My basic style is quite different, unfortunately. I can't . . . " and he paused, straining for words. "Well, I don't want to make myself sound too bad. After all, we are trained and encouraged to promote ourselves. But Rubinstein had an ease, a freedom and a clarity that I would like to develop. But I know better than try to imitate him. It wouldn't work because nobody would recognize it anyway."

One thing that should make Arthur Greene's life a little easier is the $17,000 he won with first place. It is one of the largest stipends in music. "I already have the check," he purred.

This Friday he gets the second of his awards, an appearance with the Philadelphia orchestra under Raymond Leppard, probably in the Brahms B-flat Concerto again.

And next Jan. 7, as another reward of the Kapell Competition, Greene will perform that ultimate event in the career of any musician in the United States -- a Carnegie Hall recital. In Washington, he will perform at the Phillips Collection.

Greene began playing at "4 or 5" with his mother as his teacher, at their home on Manhattan's Lower East Side. Then the family moved to the idyllic little town of Sheffield, Mass., in the Berkshires. Greene went to a prep school without a music department and got a bit out of touch from music. Then at Yale, he said, "The most valuable thing was finding people my own age who cared about music the way I did." For that reason Juilliard, which he attended for two years, was "hog heaven." "We would sit around for hours in the cafeteria talking about nothing but fingerings, and things like that."

Later, one of his teachers was the renowned Leonard Shure in Boston. "He made it clear from the beginning that he was more than just a coach. He was very systematic. He started from scratch. And he could be difficult. At the beginning, especially, he would scream at me."

And in the past year or two, Greene has been working with noted pianist Richard Goode.

When he is not concertizing, Greene is now at the State University of New York at Stony Brook, where he is on the verge of getting his doctorate. Next year he will join the faculty of the University of Iowa, he said, "but I will be encouraged to tour and play as much as possible."

One plan of his following the Kapell Competition is to buy a new backpack and do some hiking in the Berkshires.

Is there time for more in his nonprofessional life?

"Well, I have a very tumultuous love life," he answered, dissolving into gales of laughter. "And I'm not going to tell you any more about it."

For 99 out of every 100 contestants in a competition, playing the Brahms B-flat would be a mistake. It is an enormous challenge, and is really meant to be played only by the masters. But Greene assumed the risk and won -- in more ways than one.

He was correct that the name Rubinstein did not flash to mind. But in retrospect one can hear the influence, in the phrasing and in the pacing especially. The performance was unrushed but was propelled by unflagging impetus and was strikingly steady rhythmically. Articulation was sometimes startlingly clear and accurate. The phrasing was invariably sensitive. That haunting mystery that is one of the many levels that Greene referred to in this colossal work was at all times evident.

It was virtuoso reading. But that was not what most mattered about it. For above all one was conscious throughout that here was a mature musician -- one of intense concentration and seriousness of purpose.

The two runners-up in Saturday night's finals, David Allen Wehr, 29, and Nelson Padgett, 26, were also impressive. That is probably why the judges finally decided to declare them as tied for second place, with no award for third. Each received a $7,500 prize.

One of the judges, the celebrated pianist Emanuel Ax, explained later, "I just didn't want to hurt anybody."

Had it not been for the presence of Greene, Wehr would have made a noteworthy first-place winner. His interpretation of the Rachmaninoff Second Concerto had balance, impetus, lyricism, clarity, sensitivity and a sure sense of direction. He produces a lean, resonant sound. But lovely as the Rachmaninoff is, it is not a masterpiece on the level of the Brahms B-flat, especially in a fine performance -- and that is what Wehr found himself up against.

Padgett also played the Brahms B-flat -- and that was a lot of Brahms for one evening. The notes came easily to Padgett, but he had not digested the work's deeper implications to the degree Greene had, nor was his playing comparably assured.

The orchestra also let him down, with often errant pitch and ragged ensemble. Then it turned around and played the same work impeccably with Greene.

Several months ago Istomin was asked what would be necessary to make the competition a success. "It will depend on the quality of the competitors," he replied. He got what he had hoped for.