The president and Mrs. Reagan began a marathon of ball-going last night with a visit to the American Legion's banquet in a capital celebrating both the inauguration and the hostages' freedom.

They got a little rowdy at the Sheraton Washington.

"I think we've taken our quota of time here . . ." said President Reagan, standing next to Nancy Reagan on the platform. In the spotlight, they looked regal.

"Boooo!!!" the crowd roared upon hearing that their time with the presidential couple at the Sheraton Washington was up.

"There's wonderful music to come," said Reagan.

"Dance!" said one voice in the crowd. "Dance!" came a few more voices in the crowd.

"You're singing our song," said Reagan.

Then came the chant, like a concert audience demanding an encore: "Dance! Dance!"

But the Reagan's didn't.

Then, Ray Charles came to the piano and sang "America the Beautiful," while the Reagans looked on. More whistles, more whooping, more applause.

"It was worth $2,000 to hear Ray Charles sing 'America the Beautiful' to Ronald Reagan," said Kay Kelton, a Bush friend from Dallas, as she made her way over to the table where two other Bush friends, Joanie and Bob Holt, from Midland, Tex., were sitting. They sipped California champagne and raved about the inauguration -- even though it wasn't George Bush's inauguration as president.

"Oh, that'll come soon enough," said Joanie Holt, in pale pink chiffon, cheerfully.

A few feet away at another table, Jim Baker, Reagan's chief of staff, in white tie and tails, was sipping champagne. "This is the first time I've really had a chance to relax," Baker said.

His law partner Michael Butler spotted him. "Can you bring me a drink, waiter?" Butler asked Baker. "The last time I saw you like that was at the Alibi Club Dinner a year and a half ago."

Baker and Texas friends lined up in a row for a photo. Their wives sat in chairs, in a line in front of their husbands. "Smile, Jimmy," a friend called out to Baker.

At one point in the evening, the ballroom was so packed that people were not allowed in at various entrances. One announcement warned, "If you are going to the restrooms, take your husband or wife with you because you may not get back in."

As the evening wore on, tempers flared. Hundreds of people had to wait outside entrances to the ballroom when the fire marshall declared it too crowded. At one point a shouting match occured between a New York man and a uniformed official who was telling the crowd to keep back. "I'm trying to keep you abreast of what's going on in there," said the official.

"Let these people in!" shouted Tom Palka from Long Island. "My wife has been in there two hours and i can't get back in!"

John Barlett, from Fort Worth, Tex., paid $12,000 for six boxes at the ball and was stranded outside. "The house majority leader is in my box," said Barlett, "and I can't get back in. I'm a Democrat, but I came just for the ball because. . ."

"Because he's got more money than sense," said Ray Sanders of Dallas.

"Precisely," said Barlett.