When the Kennedy Center salutes Aaron Copland, you have, in effect, one national monument bowing to another.

That's what happens in the first broadcast in the new PBS series "Kennedy Center Tonight," which may do for the Kennedy Center what "Live From Lincoln Center" has done for a rival establishment. "Aaron Copland: A Celebration" will be simulcast this evening at 9 p.m. on WETA-TV (Channel 26) and (in stereo) on WETA-FM, 90.9.

Piling monument, upon monument, the Lincoln Memorial also gets into the picture -- naturally, since Copland is one of the most distinguished contributors to the Abraham Lincoln industry. Near the beginning of the 90-minute special, the composer is shown walking slowly toward the memorial while music from his "Lincoln Portrait" plays in the background. Near the end, with Leonard Bernstein conducting the National Symphony and Copland narrating the "Lincoln Portrait," the camera moves out of the Kennedy Center to the memorial. It focuses on the carved words of the Gettysburg Address as Copland's voice reads them, then shifts to a group of tourists at the monument who look uncannily like a Norman Rockwell painting -- particularly the little girl with braces on her teeth.

Then Copland's face is superimposed on the stone tablet he is reading: "government of the people, by the people and for the people . . . " and finally there is a fade back to the Kennedy Center, where Bernstein, his face transfixed with the anguish and glory of it all, is leading the orchestra through the last few bars in a kind of interpretive dance.

Corny? Yes, but it may also be the definitive audio-visual treatment of "A Lincoln Portrait." It is television doing what television does best, and it is the climax of the Aaron Copland tribute to end all Aaron Copland tributes -- at least until his 90th birthday in 1990.

The telecast focuses on the NSO's Copland tribute of last Nov. 14, including performances of the "Fanfare for the Common Man" conducted by Mstislav Rostropovich and Copland conducting the jazzy second movement of his Piano Concerto and "Appalachian Spring." But some of the best footage is taken in rehearsal or from old films: Martha Graham dancing "Appalachian Spring" and scenes from "Of Mice and Men" and "The Heiress" with Copland's soundtrack music linked to the images for which it was written. One of the most enlightening and entertaining segments is the composer's reminiscence of how a quick rewrite of the background music stopped preview audiences from laughing in one of the most tearful scenes from "The Heiress."

The telecast will have a special dimension for fans of the National Symphony with its many closeups of the orchestra in rehearsal and in concert: Fred Begun stalking his tympani like a panther, Toshiko Kohno seamlessly weaving a flute phrase into "Appalachian Spring," vies of the podium from behind the splendid long hair of Jacqueline Anderson and the hands of Dotian Carter caressing the strings of her harp.

A is natural on such occasions, host Hal Holbrook tends to overstate the importance of the honored subject. Without ever quite saying it, he manages to give the impression that Copland invented American music -- an enterprise in which he was assisted and often preceded by people named Gottschalk, Ives, Gershwin, Siegmeis and Thomson. But a just assignment of credits gets complicated, and complication is not one of the things television does best.

The PBS series of which tonight's show is part is produced by WQED in Pittsburgh, and will continue next month with a program on Duke Ellington.