Aaron Copland is bringing this week's National Symphony audiences a dazzling program of music by four of the finest American composers of our time - Sambel Barber, Irving Fine, David Del Tredici and the composer-conductor himself.

From Barber he is taking a superb composition in a classic vein, the Capricorn Concerto. There is no zodiacal significance underlying the music Barber wrote in 1944. The name is simply that which gave to the house the bought not long before in Mount Kisco, N.Y. The concerto is in the style of a baroque concerto grosso, with solo roles for flute, oboe and trumpet over strings.

The second work on the program is by Irving Fine, a Bostonian who not only studied with Boston's Edward Burtingame Hill and Walter Piston, but followed in their footsteps by joining the music faculty of Harvard University where he died prematurely in 1962 at the age of 47. Copland has written about Fine, "all his compositions, from the lightest to the most serious, 'sound': they have bounce and thrust and finesse: they are always a musical pleasure to hear."

From Fine's select repertoire, Copland has chosen his "Serious Song," an extended symphonic poem for full-string orchestra.

There is a touch of real charm in Copland's juxtaposing Fine's music with David Del Tredici's "Lobster Quadrille" because both Del Tredici and Fine found major inspiration in "Alice in Wonderland," and both men wrote pieces called "Lobster Quadrille." Fine set six "Alice" poems for chorus with piano.

Del Tredici, however, has been making quite a career of "Alice" pieces for a decade, since he wrote "Pop-Pourri" in 1968.

This is a choral work in which mingles Jabberwocky with the Litany of the Blessed Virgin Mary, all the while having himself a polyphonic ball by sounding one of the final notes 13 - "Tredici" - times, and in other sophisticated musicianly ways putting a highly personal stamp on the piece.

Since that time Del! Tredici, who turned 41 only 10 days ago, has become the music world's No. 1 specialist in "Alice."

This week's "Lobster Quadrille," which followed "Pop-Pourri" in 1969, had its world premiere in London under the same hands, those of Copland, that will conduct it here this week. It is scored for full orchestra to which, for the sheer fun of it, the composer has added mandolin (shades of Verdi and Mahler!), banjo, accordion and two saxophones.

The Quadrille was followed in 1972, by "Vintage Alice"; "Adventures Underground" was next in 1973, "In Wonderland" in 1974, and "Illustrated Alice" in 1976. A year earlier Del Tredici wrote the biggest public hit of all his music thus far, "Final Alice."

George Solti and the Chicago Symphony gave the world premiere in October,1976. Sir Georg was working on the score at the time he was conducting the Paris Opera here at the Kennedy Center that Bicentennial Year. I happened to be visiting with him in his room at the Watergate Hotel when a phone call came from Del Tredici.

"David," Solti began immediately, in that thrusting way of his, "you simply must cut it. By at least 10 minutes. It is too long. Think it over and come and see me Monday morning at the Drake Hotel."

Del tredici recalled that conversation a few days ago. "It was about 55-minutes long then," he said. "I made some cuts here and there. And when Solti conducted it, it still came out 55 minutes!"

The composer says his "first acquaintance with the world of Wonderland came at a relatively tender age (11) and in a rather distorted form: I sang the role of the White Rabbit in a grammar school musical version of "Alice."

Once having been bitten, he saw no reason to end his "Alice" trips. Asked if "Illustrated Alice" marked the end of the line, he laughed and said, "No. I thought it might, but now I am doing two more. One is for Felix Slatkin and the St. Louis Symphony which commissioned it." The other one is not yet public information but it will be on the concert docket season after next.

Del Tredici's work has been prominently performed in Washington before now. A Coolidge Festival in the Library of Congress brought one of the early performances of a work commissioned by the Library's Koussevitzky Foundation. Called "Syzygy," it is a setting of two poems by James Joyce. You can find the title in your dictionary, but Del Tredici goes farther than Webster as he explains that "through astronomy, zoology and mathematics, the word is used," while in his mind it "always looked like some other, uncreated word run backwards, mirror fashion." Thus, in "Syzygy," the music goes, as the composer points out, "exactly backwards from its midpoint (but in a reorchestrated form)."

Copland has put his opinion of Del Tredici into words as well as in programming the "Lobster Quadrille." "That rare find among composers," he wrote of the young man, "a creator with a truly original gift . . . I venture to say that his music is certain to make a lasting impression on the American musical scene."

The final work on this week's program has already made its lasting impression on the scene. It is Copland's Third Symphony.