Some parties are great places for taking care of important business. Other parties are for more preliminary things.

For their dinner in honor of Bill Brock, the U.S. special trade representative, furrier Sidney Zlotnick and Evelyn, his wife, managed to put together a guest list that included three cabinet secretaries (the three B's -- Block, Brock and Baldrige), one senator (Nancy Kassebaum), a Supreme Court justice (Stevens) and a platoons of ambassadors.

"It should be interesting," mused the hostess early Tuesday evening as the guests were arriving. "The Japanese ambassador and the special trade ambassador . . . I'm sure they'll have a lot to talk about."

No doubt. Just like the ambassador from the European Communities, Roland de Kergolay, and John Block, the secretary of agriculture. "About the grain agreements," said de Kergolay.

"Ah yes, the grain agreements," said Block.

"It will be time to renegotiate the wheat agreement soon," said de Kergolay.

"Yes, it will," said Block amiably. His mind was on the Boston Marathon, actually. He's running in it. Practices every day. "But I never run the 26 miles until the actual day."

Commerce Secretary Baldrige was talking about steer roping as the waiting cleared away the beef. "I go down to a place in Virginia to practice.They didn't know who I was at first. I just told them I worked for the government. And you know what they said, even then? 'Just cut the son-of-a-bitch.'"

What?

"The budget, the budget, said Baldrige.

There were toasts and cheers for Brock, including one from Justice Stevens. "This one is from the ivory tower," said Stevens.

"Is Justice Stevens from Illinois?" whispered Midge Baldrige.

"Sometimes I think no one in Washington is from Illinois but us," Sue Brock whispered back.

"Yes, no one but the Brocks," agreed Baldrige sympathetically.

"We're the Blocks," said Sue Block.

"Oh dear," said Baldrige. "Of course."

Everyone retired to the salon, and then it was 11:30 and time to go home.

"You can count on me, Mr. Ambassador," said Antonio da Silveira, the Brazilian ambassador, to Brock as he exited. "I will always give you correct information."

"Isn't it lovely? said Evelyn Zlotnick, as the last guest bowed out the door. "I always think dinners like these cement ties."

Kathy Cronkite, wasn't the only person with a famous last name at the book party the Ikards, socialite Jayne and lawyer Frank, gave for her last Sunday afternoon, but she was the only one autographing copies of her new book, "On the Edge of the Spotlight," in which children of the famous talk about being children of the famous. (The consensus: it's not easy, but on the other hand . . . )

"I just talked to Roc Brynner," said Cronkite. "He's done a book about his experiences that's supposed to be marvelous -- half fact, half fiction." Zsa Zsa Gabor's daughter may do a book, too. This could be a growth industry.

"I'm a little hoarse," said Cronkite, who'd endured a three-hour stint on the Larry King radio call-in show.

"It wasn't too bad, but you really get some strange calls at 3 in the morning."

Like the woman who phoned in to say that she'd grown up hating the rich. "She said that she didn't anymore, but her daughter does, and what should she do about it?

"I told her you have to teach your children to love people no matter what they are, white or black, rich or poor -- you know, the whole liberal rap," said Cronkite.

And?

"She said 'Uh-uh,'" Cronkite answered. "And then she hung up."

Others on the edge of the spotlight at the party included:

Chris Wallace, son of "60 Minutes'" Mike, standing talking to the first lady's press secretary, Sheila Patton.

"How are things at the White House?" said Wallace. "How is the first lady now that the president's home?"

"She must be fine," said Patton. "I haven't heard from her in two days."

Alex Haig, son of the secretary, came with his wife, Wendy. He's 29 years old, but could pass for 19. "I know, I know," he said. "I guess it will be an advantage some day."

"We don't pay too much attention" to local tempests, said Wendy.

"We watch Johnny Carson," said Alex Haig. "He's a good barometer for what's on the country's mind."

They played folk music at the party for the Karen Silkwood fund on Wednesday night. It wasn't always in tune, but the crowd of 400 was so buoyed up they hardly noticed it.

"We have a right to answers, we have a right to pound our fists, and reopen this case!" said Richard Rashke, the journalist who's just written a book called "The Killing of Karen Silkwood."

Rashke took questions from the audience, and soon the evening had taken on the feel of a good thriller.

"Do you believe there is a black market in plutonium?" one man wanted to know.

"Do you know who killed her?" asked someone else.

"Why won't the FBI say who did it?"

What happened to the 40 pounds of plutonium that disappeared from the Kerr-McGee plant?"

What led you to rule out suicide?" The audience snorted with derision at this last, heretical remark, which was followed by a film, a pep talk, and a solicitation for funds to carry the Silkwood case to the Supreme Court.

"Part of the book sale money is going to the fund," said a woman selling the book, which was moving briskly.

"Well, if it's all the same to you," said a man fingering his wallet near the book stand. "I think I'll wait until I can get it at Crown."

They didn't bring their instruments along, but they've been together so long that their conversation is practically a symphonic arrangement anyway.

The NSO's senior artists crowded into Lillie Lou Rietzke's Watergate penthouse Monday afternoon to celebrate the return of conductor emeritus Howard Mitchell, who was back to conduct for the orchestra's birthday.

His musicians were as pleased with the whole situation as Juliard students on a field trip, and stood about cracking jokes and toasting various things with the fine champagne.

"Isn't this just grand," said Mitchell, as William Brock was welcomed into what Reitzke, a longtime NSO backer, called the symphony family. (A decorous way of saying that he'd just joined the symphony's board of directors. This seems to be his week.)

"We've all been through some traumatic days," said Brock, "and we've been blessed with a healthy president."

"Hear, hear," said people in the crowd.

"Say, would you object if we played the National Anthem tomorrow night," said Mitchell suddenly. "I just feel like that all of a sudden." Nobody minded. The concert the next night was a 50th birthday for the symphony and a celebration for the Maestro.

Soloist Eugene Fodor, the cowpoke violinist, was sitting quietly near the cookie plate. He lives in Colorado much of the year, and has been frightening his fans for years with his horseback riding and other potentially finger- mangling pursuits. But Monday, in tweed jacket and velvet trousers, he was the picture of a city slicker.

The real fun came when the party squeezed out onto Reitzke's narrow curved terrace for a picture.

Closer, closer, closer, the photographer demanded.

"This reminds me of the first tour the orchestra made to South America," said Dorothy Stahl, the co-principal cellist. "I was afraid of flying. Howard had to hold my hand."

Oh, you know you loved every minute of it," said a few people in chorus.

Rietzke has a roomful of symphony momentos -- programs, flyers and so on.

"Oh, South America was a triumphant tour," said Rietzke. "And of course, the president is very involved with those countries now."