What is the Fourth of July?

If you are on the Monument Grounds, waiting for the Beach Boys and just playing, it's fun and a few more throws of the frisbees.

But if you are backstage, holding a list that announces the starting times of 7:05 p.m. for Joan Jett, 7:45 for the Oak Ridge Boys and 8:30 for the Beach Boys, and it's 7:45 and none of the acts are there, you develop a smile.

Sherrie Levy, one of the press liaisons for yesterday's entertainment, had a wonderful toss of her short red hair and a thin but patient smile as she explained, "The groups are somewhere between Philadelphia and here. The Oak Ridge's equipment truck is here."

Somehow that confidence didn't spread around to the technicians, the celebrity roadies and the crew from WAVA-FM, who emceed yesterday's event, because the word was spreading that the Park Service didn't want to delay the fireworks too long. And the crowd was getting restless.

To fill the gap between the Four Tops and the other headliners, a pick-up band played and then it was back to canned music. Bruce Springsteen's "Born in the U.S.A." started screaming over the loud system.

"The Park Service asked us to cool down the music, talk a little more, because the crowd was getting restless," said Alan Goodman, the general manager of WAVA. "I can't find the Kate Smith," cracked one of his lieutenants, Loo Katz.

And talk they did. "Are you having a good time?" asked deejay Don Gerinimo. A roar and a few unofficial fireworks. "Isn't this the best damn thing you have done for free?" A modified roar. "How about doing at the count of three, 'We love the Beach Boys!' " They obeyed.

At 8:32 p.m. the Beach Boys' caravan of buses arrived and out poured Joan Jett, the Oak Ridge gang and the California wonders. The live music started again at 8:55 p.m. At 9:25 Mike Love of the Beach Boys introduced television's mass of mean muscles, Mr. T. Five minutes later Mr. T. asked the crowd to back up. Then at 9:30 Love announced, "The Park Service has asked us to end the show as quickly and quietly as possible." A tornado of boos echoed around the grounds. "I don't know what to say," answered Love. "Let's take a vote. Let's promise to be kind to each other."

Around 9:40, the notes of "California Girls" wafted over the backstage area, where there was an audible sigh of relief. Smiles returned to the special guests fenced off in the Park Service's picnic area and a few -- those with some energy left -- got up to dance. And the stagehands continued loading all the trunks of equipment into the rented vans.

Earlier in the day, a few of the performers had tried to capture what the Fourth means. Right now to American-born but Britian-residing Katrina Leskanich, the lead singer of the British group Katrina and the Waves, the day meant success. When she stepped off stage, she gasped and said the American audience was "intimidating."

"So many people," she marveled. Last Fourth of July, she said, "I was being dead miserable wondering when I was going to make it in rock 'n' roll." This year she's hot on the rock 'n' roll circuit.

On last year's holiday, Bobbie Brown, a member of the New Edition, was home in Boston at the movies seeing "First Blood." Surrounded by the other members of his group, all dressed in purple sparkling jackets, Brown said he was "happy to be here." Both groups are tasting what America likes to call overnight success.

And Tim Goodman of Southern Pacific was saying the Fourth meant memories: "The Fourth of July in the capital -- that's something I will tell my grandchildren."

And what is the Fourth of July if not a spectacular and unique ending?

At 9:50 p.m., right in the middle of the Beach Boys humming about "Good Vibrations," the Park Service gave the go-ahead for the fireworks. Giant lilies burst over the Reflecting Pool. And the Beach Boys kept rolling through "Lucille," and "Help Me Rhonda," as the crowd looked to the sky and snapped fingers and danced.

And when the fireworks stopped at 10:15 p.m., the gang that has come to symbolize the Fourth in Washington was still singing "Fun, Fun, Fun."