IN 1925 WHEN Aaron Copland's Organ Symphony was given its world premiere by the New York Symphony under the baton of Walter Damrosch, the solo organist was Nadia Boulanger.

In 1938 when the Dumbarton Oaks Concerto received its world premiere at the famous Georgetown estate for which it was named, the conductor of the orchestra was Nadia Boulanger.

In 1956 when Grace Kelly of Philadelphia married Prince Rainier of Monaco, the music for the glamorous ceremony in the Cathedral of Monaco was selected and in large part conducted by Nadia Boulanger. The elegant programs given to the wedding guests described Boulanger as "Maitre de Chapelle de S.A.S. le Prince Souverain."

On Friday, Nadia Boulanger, the most remarkable woman of 20th-century music, will be 90. And if her failing health permits, she will spend at least a part of the day doing exactly what she has been doing for early 60 years at the very same address: giving peerless advice to a promising young composer.

It was to that same address, 36 Rue Ballu, that Aaron Copland went in the fall of 1921 after a summer of study with Boulanger at the brand new American School at Fontainebleau, outside of Paris. In recent years, another line has been added to the address: It is now also called "I Place Lili Boulanger," in memory of the greatly gifted younger sister of Nadia, who died in 1918 at the age of 24.

There can be no question that Nadia Boulanger has been the most influential teacher of music in this century. Even a very abbreviated list of those who have studied with her, both in Paris and during her several visits to this country, demonstrates the way in which her principles have spread throughout the world of music into at least three generations of composers.

Copland was the very first of the Americans.He was so excited after first hearing Boulanger in a class that his name headed the list of those to be enrolled in the new Fontainebleau school. Following him from this country were such now-famous names as Virgill Thompson, Roy Harris, Walter Piston, Elliott Carter, Mark Blitzstein, and younger men like Arthur Berger, David Diamond, Irving Fine, Harold Shapero, Easley Blackwood, and Russell Woollen. Among the youngest of the last generation to work with Boulanger have been two from the Washington area, Robert Shafer and Reilly Lewis.

You think for a moment of the vast differences between the basic clarity, the sophisticated elegance and rootsy feeling of Virgil Thomson, and the stringent economies, mingled with extreme rhythmic complexities of Elliott Carter, and then contrast these with the highly romantic style expressed in solid symphonic forms of Walter Piston, you get a minute glimpse of one of Boulanger's basic attitudes: to find and help each composer to develop his own individual style with excellence.

By 1957, Jean Cocteau summed up both her achievement as a teacher and her immutable standards in teaching when he wrote: "There are those names which escape from the cyclone of indifference, and the ogre of daily events. The name of Nadia Boulanger is one of these, for it has attained a position of nobility that makes it invisible to the mediocre." Cocteau continued, "It is rare that a young musician intrigues us, or that his work at least partially opens a door, without his disclosuring that he is a pupil of Nadia Boulanger."

By the time she was 30, Copland says, "Mademoiselle knew everthing there was to know about music, she knew the oldest and the latest music, pre-Bach and post-Stravinsky and knew it cold. All technical know-how was at her post-Stravinsky and knew it cold. All technical know-how was at her fingertips: harmonic transposition, figured bass, score reading, organ registration, instrumental techniques, structural analyses, the school fugue and the free fugue, the Greek modes and Gregorian chant."

Boulanger's father, Ernest, was a professor at the Paris Conservatory, and a Prix de Rome winner. Her mother was the daughter of a Russian, Prince Micheletzky. Entered at the Conservatory at an early age, Nadia, when she was 15, won its first prize in harmony. One year later, she carried off first prizes in organ, in accompaniment, and in Gabriel Faure's class in fugue. No wonder then that Aaron Copland thought, that first time he lestened to Boulanger lecture - it was in a harmony class in which she was discussing Mussorgsky's opera, "Boris Godunov," - "I had never before witnessed such enthusiasm and such clarity in teaching. I immediately suspected that I had found my teacher." He did raise one very large question, however, before his final capitulation:

"No one to my knowledge had ever before thought of studying composition with a woman." Remember, this was 1921. "The idea was absurd on the face of it. Everyone knows that the world has never produced a first-rate woman composer, so its follows that no woman could possibly hope to teach composition. Moreover, how would it sound to the folks back home?"

If, to the names of the Americans who have studied with Boulanger, you add those from such other countries as Japan, Poland, Chile, Norway, Turkey, England, and many more, you see yet more clearly the ways in which, first through her own teaching, and after that, through the teaching of those whom she taught, Boulanger's ideas on music have pervaded our time."

A single example will illustrate the directness and strength of that pervasiiveness: In Copland's jazzy Piano Concerto, which he wrote in 1926, it is easy to hear indeed it is impossible not to hear clearly, various elements that come into prominent play in Leonard Bernstein's "west Side Story" of 1958. This kind of influence could be multiplied hundreds of times in music written in the past half century.

Boulanger's contributions have, however, by no means been confined to the classes she has taught in Paris in the history of music, harmony, counterpoint, theory, accompaniment, and composition, classes she has continued each summer at Fontainebleau except when war made them impossible. In 1952 she took over the direction of that school, following the great French pianist Robert Casadesus in the top spot.

For Boulanger has always been a performer as well as a teacher. Not only did she persuade her young pupil Copland to write an organ symphony so she could play it with the Damrosch orchestra, she also played it with the Boston Symphony in that same season. In subsequent seasons she became the first woman to conduct regular subscription concerts of the Boston and Philadelphia orchestras, the New York Philharmonic, and the Royal Philharmonic in London. To these she added appearances with the Paris Conservatory Orchestra and the London Symphony. In 1937, Boulanger persusded a record company to permit her to make recordings that were of historic significance, as she took into a Paris studio an ensemble of singers and instrumentalists of her own choosing to record, for the frist time, a wide selection of vocal works by Claudio Monteverdi, whose music was, at the time, largely unknown to any public.

(That recording fomerly issued in this country on Angel COLH 20, is still occasionally available on Seraphim 60125.)

Some today who hear Boulanger's first recording of Monteverdi immediately put on very superior looks and indignantly demand, "What is she doing with the PIANO in the music!" What they do not realize is that in 1937, even the historic work of Wanda Landowska and the pioneers of baroque performance practice had not yet reached the point where the piano, superbly modulated, seemed out of place. By 1952, however, Boulanger having played the piano in the earlier recording with astounding, fluent delicacy, had switched to her exquisite Pleyel harpsichord.

During these same years, Boulanger campaigned effectively on behalf not only of Monteverdi and early French music, but also for such rare items, in those days, as the Schuetz Passions, and the Faure Requiem. Today the Faure is a standby for many parish choirs, but Boulanger, who was later to cite it as one of the foundation stones of contemporary music, was among the first to perform it with major orchestras. It is not surprising, then, that when His Royal Highness Prince Rainier wanted the very finest in music for his wedding, he turned to Boulanger.

Boulanger visited this country frequently after that initial foray to which Damrosch invited her in 1925. In 1938 she came, not only to present concerts with the ensemble with which she had recored Monteverdi, but to accept some of the many invitations to teach. It was at that time that she first taught in this city at the Washington College of Music, as well as, in later years, at the Curtis, Peabody, and Juilliard schools of music, the Longy in Boston, and on the campuses of Wellesley and Radcliffe. During a visit to the Stravinskys in Los Angeles she joined the composer in a performance at Mills College of the new sonato for two pianos.

At no time during her long years as a teacher were Boulanger's studens, either class or private, confined to composers. Among the famous names that have worked with her have been men far more widely known in other fields, like conductor Igor Markevitch, pianists Clifford Curzon, Dinu Lipatti, and Dalton Baldwin, and harpsichordist Ralph Kirkpatrick. And there is a satisfying touch to the recent appointment as director of the Peabody Conservatory of Elliott Galkin, musicologist and historian of music, who studied with Boulanger in Paris.

In addition to that historic occasion when she conducted the first performance of the Dumbarton Oaks Concerto, which Robert Woods Bliss commissioned from Stravinsky as a wedding anniversary gift for his wife, Mildred, her appearances in Washington never failed to make a vivid impression.

During her last visit to this city in May of 1959, Boulanger lectured for the now-defunct Institute of Contemporary Arts, a venture headed by Robert Richman, which for years brought much of the newest and finest contemporary music to Washington. At the end of the dazzling lecture, in which all of her customary charm and wit had been brilliantly mingled with her keen intellectual perceptions, Boulanger offered to answer questions from the audience. One listener rose and asked if Mademoiselle would be good enough to "say a few words about the origins of contemporary music." Taking no more than a few seconds for thought, Boulanger began unhesitatingly to list works which she called "landmards in the development of what we think of as modern music. Others," she noted, "might well have been added."

She began to the astonishment of some, with the Faure Requiem, which was written in 1887. She then proceeded to name, in almost strict chronological order, and without reference to notes of any kind, 75 compositions ranging from Satie and Debussy through Stravinsky, Schoenberg, Bartok, Hindemith, and Messiaen to Copland, Bernstein, and Blackwood.

It was, in its sponteneous delivery, its impressive display of an imtimate knowledge of the whole world of music, and in its steady cumulative power, one of the most overwhelming moments in my experience. When she finished, the applause was a roar of appreciation for a woman who, at the age of 72, had never for a moment lost her enthusiasm for the old or the new in music.

That enthusiasm she transmitted unsparingly to those who came to work with her. In one of her most humorous observations, Boulanger once divided the applicants for her classes this way:

"There are three classifications of applications: those without money and without talent; those I don't take. Those with talent and without money; those I take. Those with talent AND with money, those I don't get." When it came to work, Boulanger expected from her pupils the same unsparing approach that was always hers.

Nelita True, a member of the piano faculty of the University of Maryland, tells a story that illustrates the kind of discipline that has always controlled Boulanger. True says that several years ago, while she was a member of a Boulanger class, a change in the class schedule was announced which conflicted with True's plan to go Moscow, where she had been invited to play.

When she explained this to Boulanger, saying that she would sorry to miss the class, Boulanger replied, "All you are going on a vacation! I have never taken a vacation in my life unless it coincided with my work!"

At 90, Boulanger's work is over. Her health, which until recent months, had carried her through decades of unremitting work, has now failed her. She is nearly blind and much of the time must use a wheelchair. But in the far larger sense, the work which Nadia Boulanger has been doing for nearly six decades will never come to an end.

Aaron Copland has written about his famous teacher, "The Influence of this remarkable woman in American creative music will some day be written."

As Copland would be the first to agree, that influence has already been written - in great quantities of the finest music this country has produced.