Let's say you're a sparkling young pianist, increasingly sought after both in your native Soviet Union and also abroad, and it's your night to play in the capital of the West.

The entire Moscow Philharmonic is in place at the Kennedy Center -- senators, cabinet members, ambassadors in the audience -- and where the hell are YOU?

Sound asleep until 8:15 (the concert was at 8:30), and at 8:50 you finally get to the Concert Hall, just in time for your dazzling interpretation of the Prokofiev Piano Concerto in C.

The orchestra played its first offering, then paused for the piano to be wheeled in, at a smashing concert Saturday night by the Moscow Philharmonic.

Soloist Alexandr Toradze, fresh from his harrowing discovery he had been napping instead of preparing his soul for the great labor of the night, strode to the instrument. None of the audience knew how close he came to missing it.

He sat down at the bench. Then got up and adjusted it. Then sat down. Then got up. Then faced the audience with his arms crossed over his chest and his head bowed in the universal gesture of mea culpa. The audience clapped its sympathy. In a minute, another bench was fetched and everything was fine from then on.

At the reception afterward, J. Paul Austin, who is chairman of Coca-Cola Co., explained why he was paying for the party:

"I believe in communication," he said.

In fact, the soloist of the evening was silver medal winner of the 1977 Van Cliburn Competition for young artists, and the Cliburn Foundation in Texas wanted to honor Lexo, as he is known to friends.

They asked Coca-Cola to help out, and the Atlanta corporation was glad to. Austin said there was nothing particularly significant about the party's honoring Moscow artists -- the company does this sort of thing for various cultural groups.

Coca-Cola will be sold during the Moscow Olympics, however, and it seemed a nice gesture to feast the Russians on shrimp, king crab, babas au rhum, etc. With strawberries. And whipped cream.

Lexo, who kissed women's hands when they told him he was divine, thus causing them to virtually swoon, eventually was sat down and fed as much seafood as he could manage.

Asked how in the world he developed the discipline to nap until the very instant of performing, he said it was a horrible mistake. He had never done it before, he said, he felt it was the worst possible thing to do.

"It makes you feel entirely too comfortable," he said. Artists, before they perform, almost always go through a leisurely period of anxiety in whichd they psyche themselves up to do their damnedest when they go on stage.

In Lexo's case, the nap seemed to do nothing but good, however. With him were Barbara Burris of Washington and Martha Hyder of Fort Worth, childhood friends of Cliburn.

"You know how it is in Texas," said Burris."Everybody is so proud of Van Cliburn, a Texas boy. So when the Cliburn competition began, we were all behind that, and with Lexo coming to America to play, we wanted to honor him. So that's the dTexas and Cliburn connection."

Another Washington woman from Texas, Scooter Miller, who has long been a wheel in symphony music committees here, took on the chores of arranging all the details.

Yesterday the orchestra headed for New York and then 10 days in Mexico for concerts.