Theatrical legend and impresario Joshua Logan plunked his bowling-ball frame into a couch and took a fast look at the party held in his honor last night at the home of American University president Richard Berendzen. This was one show that amused the hell out of him.

Grown women were sausaged into "Annie Get Your Gun" jean skirts. Scooter Miller came in "Camelot" blue-velvet robes, his orange plumed hat dipping dangerously close to a tray of egg rolls in the "Sayonara" and "World of Suzie Wong" room. Downstairs on the movie screen, Marilyn Monroe was cooing in "Bus Stop." Secretary of Defense Caspar Weinberger (dressed in black tie) wrestled with a couple or ribs under the "South Pacific" tent. Former senator Frank Church strolled by the pool where the erotic dance scene from "Pincic" was later screened.

And Logan leaned back. At 73, he has the wispy mustache of a 13-year-old and the energy to match. Still, this party seemed to hve him a little bewildered.

"You know, these kind of parties are finished in New York," said Logan, who has just finished teaching a three-week workshop at American University's Performing Arts Academy. "I think it's because people in New York are terribly afraid they won't be recognized. Washington is a much sweeter, more naive town , you know."

Guests, including Judge John ysirica and Jack Valenti, soon discovered that the Berendzen home was laid out a little like an elaborate, suburban senior prom hall: Each room had decorations and food appropriate to a particular Logan production.

With some exceptions. The "Camelot" room was filled with Indonesian artifacts and a fish tank filled with Indonesian fish, coral and stones. "I guess it's a little out of whack, but we wanted to play 'Camelot' and this is the room with the stereo," said Berendzen, who was dressed in an "Annie Get Your Gun" leather vest ("I had thi in my closet!).

Outside, under the tent, five of Logan's students revue-ed, Tony Awards Style, songs from several Logan productions. Nancy Halpin, who had the audience murmuring "Mary Martin!" after she sang "South Pacific's" "I'm in Love With a Beautiful Girl," said, "I'm in love with Josh. Who's not? It's amazing to meet someone legendary who is so loving."

Logan, for his part, was less enthralled with his students than they were with him. "I loved it and I hated it," said Logan who wore a "Bali Hai Enterprises" sign in his hatband. "I'm not used to people who aren't fascinated with what I have to say about theater. One-third were okay. For the other two-thirds it's a little like they were shopping or slumming. When I think I've said something terribly witty or trenchant, they get up and leave!"

Logan said he had "at least 10 projects on the fire," including a new translation of "Carmen," two musicals and an autobiography. But he still had a little business left in Washington -- after his students had finished singing, the master showed them how it was done.

He told the story of how young Nancy Reagan helped him get Walter Huston to play in "Knickerbocker Holiday." Then Logan sang "September Song," a hit from the same show.

I've lost one tooth ,

I walk a little lame ,

I've got no time for the waiting game . . .

And I spend these vintage years with you