The National Endowment for the Arts celebrated its 20th anniversary yesterday at the Kennedy Center with American music by a splendid young orchestra from Denver. And it continued to celebrate at a party in the center's atrium, where it was announced that NEA Chairman Frank Hodsoll would be reappointed to a second term.

The concert was by the Colorado Philharmonic, an organization of players aged 18 to 26. The orchestra, drawn from auditions throughout the country, is recast every year.

At the party, Kennedy Center Chairman -- and NEA founder -- Roger L. Stevens told the crowd of several hundred that the endowment must start thinking in terms of "centuries rather than decades."

Perhaps the Colorado Philharmonic did not quite sound like the Philadelphia Orchestra in its most dedicated allure. But the young orchestra, under music director Carl Topilow, certainly gave hope for the future of American orchestral playing. All parts of the orchestra were particularly alert; the percussion was first-rate.

But the show belonged to pianist Billy Taylor and his fluent playing of his own "Jazz Suite for Piano and Orchestra." It is a work that is so fine in its invention, sometimes really sensational, that one keeps forgetting that it seems to have no sense of direction.

The opening works were both of the kind that depended on a full-scale orchestra to make big effects. Unfortunately, big effects don't mean big ideas, and there wasn't much of the latter in Michael Mauldin's "Fagada Butte: An Epiphany."

The same was largely true of Joel Hoffman's "Between Ten," a serial work trying to reflect the heady paintings of Wassily Kandinsky. There is a structural precision in Kandinsky's work that just isn't suggested in this music -- attracted as one may be to its textures.

The most familiar work was Copland's "A Lincoln Portrait," narrated by Charlton Heston. It was preceded by a lengthy biographical summary of Lincoln's life, illustrated by projections on a screen behind the orchestra. This extension, which increased the work's length by at least a third, tended to diminish the grand composition's dignified side while inflating its pompous side.