It took nearly 2 1/2 hours in a very crowded, very hot Kennedy Center Atrium last night, but few thought that too much for a glimpse of Stevie Wonder.

"You must all honor yourselves," Wonder told the crowd at a reception honoring the Rev. Martin Luther King Jr.'s birthday. "You must understand you've done something that's never been done before -- a people's holiday.

"This is a celebration, but the amazing thing about it is that you are celebrating the beginning of what must be a commitment to demand America to get its agenda right; to demand to our own dear president that he not only talk to small children about Martin Luther King, but that he's got to participate. Talk is cheap . . . "

That statement got even more cheers than Wonder's promise to give a concert at the Capital Centre sometime soon.

"Let's hear it for Stevie!" shouted another of last night's speakers, Mayor Marion Barry.

Barry himself made it to the dais only about 15 minutes ahead of Wonder, but the crowd, which numbered well over a thousand, had no trouble entertaining itself without VIPs. The party originally was by invitation, but on Friday Barry announced over the radio that the entire city was invited. It looked as if half the city took up the offer.

Girls and boys in velvet, young women and men in sequined gowns and tuxedoes, older people leaning on canes -- all ages and races were there. There were people like Dorothy Height, president of the National Council of Negro Women and long a leader in the civil rights movement.

The King holiday, she said, has "been a long, long time coming. We've made progress, but the progress is slow."

Once upon a time, she said, "There was a movement, a drive, a sense of righteous indignation against segregation and discrimination that this holiday should rekindle.

"Progress has made some people feel we've made it. But when unemployment is high and families headed by women are poor -- that's a false state . . . Martin Luther King said we're inclined to be a 10-day nation . . . After 10 days, we go on to another problem. We need to stay by these problems."

The event -- sponsored by the mayor and his wife Effi Barry, the D.C. Martin Luther King Jr. Holiday Commission, the D.C. Martin Luther King Jr. Support Group and D.C. Women for the Martin Luther King Jr. Holiday -- also drew Washingtonians like former Redskin George Starke, who attracted a lot of klieg lights. And there were the ubiquitous representatives of sponsoring corporations, including Coors beer, which displayed a large red banner outside the door announcing: "Coors Salutes Martin Luther King Jr. National Holiday."

But the partygoers were mostly people like Sandra Barr, who grew up in Shaw and participated in King's 1963 March on Washington.

"I have a 13-year-old granddaughter who marches at the South African Embassy. Blacks haven't forgotten. I'm 46 and I see hope," said Barr.

The mayor undoubtedly would agree with Barr. "I'm very glad the nation has caught up with where we were," Barry said after recounting events from his days in the civil rights movement. "But racism and sexism are still alive -- that's unfinished business. People are going hungry -- unfinished business. Folks are out of work -- unfinished business.

"Let us rededicate ourselves to the proposition that freedom, justice and equality are something we ought to have. Freedom now! Freedom now! Freedom now! South Africa!"

The crowd roared its approval.