Maurice Andre, who is possibily the world's greatest trumpeter, is strolling through the lobby of the Watergate, carrying the tools of his trade in a small suitcase.

His eye passes routinely over people sitting there. He stops and does a double take. Andres' broad, Gallic face lights up. "Cher Maitre," he cried. He drops the little suitcase full of trumpets and rushes over to clap a bear hug on Witold Lutoslawski. There are a few minutes of rapid-fire conversation in French, and it emerges that Andre wants Lutoslawski to write a trumpet concerto for him. Many of the world's leading musicians want a concerto from Lutoslawski. Andre may turn out to be one of the lucky ones.

Tuesday night, Mstislaw Rostropovich who is one of the lucky ones, will hand Lutoslawski his baton, take up his cello and play the Cello Concerto Lutoslawski composed for him in 1970. The same program will include the world premiere of Lutoslawski's newest orchestral work, "Novelette," with Rostropovich conducting.

Lutoslawski was and is the major creative force behind a surge of notable classical composition in contemporary Poland. Like Bartok, who was an idol of his youth, Lutoslawski has reconciled an astringent modernism of style with intense emotional communications and a solid personal sense of form. The Polish national musical movement for which he is the standard-bearer is unique among the socialist countries of Eastern Europe; in his generation Russia, Czechoslovakia and Hungary, the traditional sources, have withered under political contraints.

Lutoslawski composes slowly, carefully, consigning much of his work to the wastebasket. His First Symphony took seven years (partly because World War II happened while it was being composed), and his major orchestral works so far can be and are all compiled in a single six-record album. But at 66, he is firmly established as one of the world's leading composers.

It has been a long way from the discouraging years of his youth, when he graduated out of the Warsaw Conservatory and into the Nazi invasion of Poland. He served briefly in the Polish Army, spent time in a Nazi prisoner-of-war camp and sat out the rest of the war working as a pianist in a cafe.

"During the war," Lutoslawski recalls, "all musical life was forbidden in Poland because the Nazis wanted to destroy us. Even the greatest musicians in Poland played in cafes. I played in a piano duet with another composer, and during those years I made more than 200 two-piano arrangements of everything from toccatas of Bach to Ravel's Bolero. They were all burned up in the uprising of 1944. The only work that survives from that period is my Paganini Variations."

The Variations on a Theme of Paganini (the same theme that has been used by more than a dozen composers, including Rachmaninov, Brahms, Liszt and Paganini himself) are now Lutoslawski's most popular composition -- recorded 10 times and about to begin a new life in an arrangement for piano and orchestra that had it first performance recently in Florida. What else was lost in that fire" Lutoslawski prefers not to think aobut it.

When the Nazis were destroyed, Poland felt the heavy hand of Russia, but it made its own adjustments and by the mid-1950s Polish artists began to feel a freedom that is still absent in the Soviet Union. Lutoslawski perfers not to talk about politics but will speak enthusiastically about the younger musicians in Poland -- particularly Krzsysztof Penderecki, who has reached a level of international attention at least comparable to Lutoslawski's own.

Lutoslawski explains the Polish enthusiasm for modern music: "Poles are very adventurous, very curious about new things," but history offers a further explanation.

Stalinism never took deep root in Poland, and the stifling canons of "Socialist Realism," which still support mediocrity in Russia (aided by a tightly-controlled composers' union) were discarded in Poland nearly a quarter-century ago.

The result is that not a single composer of international stature has been born and trained in Russia since the Revolution, while Poland has produced many.

Lutoslawski, looking at the remarkable development of music in Poland, treats cultures as though they were individuals and suggests that perhaps some other societies have worked so hard at producing great music that they need a rest, while Poland, with its relative freedom from past traditions, now has the vigor to move ahead. "This is very hypothetical," he says. "Please do not make it sound like a fully developed theory, but our music history has left us very well-rested for the present historic moment. We do not have a great tradition such as Germany, France or Italy, and this leaves us free to begin such a tradition now. We had a beautiful Renaissance period, but no intersting 18th century and only one star of great magnitude in the 19th: Chopin. Between Chopin and the present, there is only one great musician -- Szymanowski -- and so perhaps we are ready to produce great composers now while other nations have exhausted their possibilities, at least for a while."

Although his music is strikingly contemporary in idiom, Lutoslawski does not accept modernism as a musical panacea. He says he learned some of the basic principles of his own work from composers of the pre-Beethoven period -- and these principles can be illustrated by the two works to be performed Tuesday night.

Despite its literary title, "Novelette" is abstract music in five brief movements that will last a total of about 18 minutes. The three sharply contrasted center movements are called "First Event," "Second Event" and "Third Event"; they are preceded by an "Announcement" that presents samples of the Events and followed by a "Conclusion" which is the longest movement of the work and whose role is to release the tensions and satisfy the expectations that have been built up earlier.

After some feverish activity, a touch of comedy and vivid bursts of instrumental color in the earlier movements, the "Conculsion" is devoted largely to a long, slow-moving lyric episode by two groups of divided violins, with the other instruments providing commentaries.

The other Lutoslawski work on the program, his Cello Concerto, will be having its Washington premiere but is well-known to fans of Rostropovich through a recording he made several years ago. It is an intense, dramatic and colorful interchange between the cello and the orchestra -- as a whole and in sections, with particularly obstreperous interjections by the brass. If the "Novelette" works as well as the Concerto, Tuesday evening may see the birth of a classic.

While they were composed a decade apart, these works have some similarities. Both are relatively brief. Each of them has a series of short, rather sharply contrasted episodes after an introductory movement. Above all, both follow a pattern of exciting expectations in the short, early movements and satisfy these expectations in a longer, more substantial conclusion.

Lutoslawski uses expections and fulfillment as the basic structural pattern for many of his works -- and he considers brevity (or the impression of brevity) one of music's most desirable qualities. He feels complimented when someone tells him that his Cello Concerto seems only half as long as its 26-minute length, and he gives Penderecki his highest compliment when he says, "His 'Paradise Lost' doesn't seem nearly as long as it is."

These qualities have earned Lutoslawski more requests for new music than he can possibly fill. He is now finishing a concerto for oboe and harp for oboist Heinz Holliger and his wife Ursula, and he is also at work on a Third Symphony for the Chicago Symphony Orchestra. "I wrote the main movement but discarded it," he says matter-of-factly. "Perhaps I will save some parts of it later."

Holliger's name brings up the subject of experimental music and a reminiscence. "Holliger came to me and played all the unusual sounds he can produce on the oboe, and he wrote them down. I have a complete catalogue of all the unusual sounds Heinz Holliger can produce, but I only used some of them, when they were called for by the music."

In contrast, he feels that many contemporary composers have been exploring unusual sounds for their own sake -- building a large vocabulary but not using it to make sentences. "I remember a sentence I read in Levi-Strauss," he says. "He was talking about abstract painters, but what he says is more applicable to some composers. He said, 'These people show us how they would paint if they once had an idea of doing it.' Many composers show us how they would compose if they got around to composing."

One kind of music Lutoslawski does not get around to composing any more is piano music -- which he composed abundantly in his youth. A young Polish piano virtuoso, Krystian Zimerman, has asked him for a concerto -- and although he admires Zimerman's work, he says he cannot compose one. "All my piano concertos have ended in the wastebasket. I would love to compose a piano concerto for this young man, but it is very difficult. The piano now must be redefined; after the great period of the piano, from Choplin to Ravel, there is now nothing really new for the piano to say."

The solution found by some composers (most notably John Cage) of altering the piano's sound by putting foreign objects on the hammers or strings, is not the right one for Lutoslawski. "I hate it," he says intensely. "I hate hurting a beautiful instrument. The piano is a masterpiece of technology, and to hurt it by putting in pieces of paper or metal is barbaric. Instead, we should have new instruments -- the old ones have nothing to do with out modern imagination. The problem is that no electronic instrument has yet produced a sound like that of Rostropivich playing his Stradivarius."

As far as revolution in music is concerned, he says, "the revolutions are over; the experiments have all been tried. The most revolutionary composer is one who would write something that will survive and be played in 50 years. For that, you need music of substance and personality."

By his own standard, this makes Lutoslawski a revolutionary composer.