Misconceptions to the contrary, there simply is no such genre as black classical music. This is one of the points illuminated by the New York Philharmonic's week-long "Celebration of Black Composers," which ended with a concert last night.

The Philharmonic's enterprising set of five concerts, for the most part works unheard here before, demonstrated there is a considerable body of sometimes excellent music of a wide range written over the last two centuries by composers who happen to be black.

To quickly summarize the stylistic range of the 12 works on the three orchestral programs, without any intention of suggestion that many of them are derivatives, it might be said they stretch from Mozart all the way to first-generation followers of Schoenberg. In quality, the most exciting were those pieces by contemporary composers - particularly Hale Smith, George Walker and David Baker.

Though each of these composers' styles differs widely from the others, all are writing music of considerable substance and skill deserving a wider audience.

Smith's "Innerflexions," which received its world premiere at last night's concert conducted by Leon Thompson, was in particular a revelation. "Innerflexions" is a relatively brief, highly compressed, superby orchestrated work in the serial technique, that system of composing that eschews traditional harmony. In serial music, the message sometimes gets lost in the technical complexities, but that is hardly the case with "Innerflexions."

Smith says that he set out to "capture a moment of magic," and indeed the work has a glowing quality. The opening is a series of harmonically equivocalsustained chords punctuated with glistening highlights from the percussion. Then it goes on to a main section of solo dialogues in the brass and woodwinds, in which two instruments are often playing at the same time in counter melodies - all of this suspended over a cloud of trilling and sustained strings.

The range of timbre and pitch is large, and above all the work proves, once again, that there is nothing intimidating about atonality when it is used expressively.

Asked what composers influenced him most Smith said. "Mozart, Mahler and 'Duke,'" a reference to the late jazz giant. None of these affect the surface of Smith's composition, but perhaps in clarity of expression and compositional skill, there is a sort of kinship.

On the same program, David Baker's Cello Concerto, commissioned by the celebrated cellist Janos Starker, jazz is very much on the surface. It is primarily the jazz of a Coltrane or a Monk. The cello solo is conceived in the style of a jazz saxaphone, playing thee blues in one movement and even playing firfs in the final one.

At one point the orchestra itself even moves into the style of a jazz ensemble with the solo cello playing against a string bass in the bass viols, the woodwinds playing obligatos and the percussion the conventional jazz one. Yet at other points is the texture is highly symphonic.

This work is more than a novelty, it is fascinating and most attractive. Its composer is chairman of the Indiana University jazz department, and once played trombone with Kenton, Hampton and Maynard Ferguson, among others. The young cellist, Eugene Moye, is someone to watch.

The two Walker works performed Thursday night follow yet another esthetic. Again the composer makes an attribution to jazz, because the reflective slow movement of Walker's piano concerto is a tribute to Duke Ellington. But there is little of Ellington on the surface, aside from some common note intervals and a few turns of phrase. This movement, like the "Lyric for Orchestra" that preceded it, displays Walker's talent for gentle, unsentimental lysicism - a rare thing in any form of music these days.

His busier movements tend to be angular and highly rythmic, full of unexpected intervals that avoid the tonic and leave the harmony deliberately ambiguous. The pianist was Natalie Hinders, who performed the same work with the National Symphony last year. On Thursday night Paul Freeman conducted. The work drew a standing ovation.

Space prevents a detailed look at other works on the program. They included two violin conference. One was a partly atonal work by the contemporary Roque Cordero that retains very much the style of the virtuoso vehicle. And the virtuoso playing it was Stanford Alien, the young violinst who just resigned as the Philharmonic's only back member in order to follow a solo career. The other concerto was that of Jose White, the Cuban violinst-composer who in 1875 became the first back to play with the Philharmonic, and is very much what you would expect to be written by a classmate of Sarasatie in Paris.

Two words from the 18th and early 19th centuries were the requient by the Brazilian Jose Nunes-Garcia and the symphony by the European emigre Chevalier de Saint Georges.

An inescapable conclusion from this festival is that of the Philharmonic can do it so can the Kennedy Center - and learning from the Philharmonic's pioneering example, do it better. The Philharmonic's festival is the largest ever staged for music by blacks, and one at the Center need not be longer, but it should be different.

Now that the New York festival has demonstrated the stylistic range of classical works by blacks, there should be more emphasis on what is excellent and contemporary, New works should be commissioned, Fewer works that are already recorded should be programmed. And very importantly, incentives should be offered for white performers to bring the works into their repertories.

It would be nice to see, at last, in Washington what I have been seeing in New York this week and never seen anywhere else before - a symphoney audience that was at least half black. Sitting reasonably far back in Fisher Hall's orchestra section, the sight of a veritable sea of Afros between me and the orchestra was a pleasure to behold.