THE SMALL room off Dupont Circle is cluttered with posters and balalaikas and books in Russian and a piano and boxes and desks and records and a phonograph and picture albums and piles and piles of old photographs.

The photographs show the great days in Hollywood, when stars were stars and hundreds of them would gather on someone's lavish estate for epic hilarious parties around the pool. Here and there in a picture you might find Charlie Chaplin, Gary Cooper, Dorothy Lamour, Nelson Eddy, Wallace Beery, Fonda, Garbo, Olivier, Fairbanks, Pickford, Gershwin . . . but in almost all of them you see a sturdily handsome man with wavy blond hair, a satin Cossack-style shirt and a balalaika.

This is Gregory Titoff, usually known as Grisha, though once he was called "Mr. Balalaika," and in another lifetime he was the bicycling and pentathlon champion of eastern Manchuria.

"I met them all," he says. "I had my balalaika orchestra at the Pickford-Rogers wedding reception serenading the guests, and everybody was there, everybody you ever heard of. I was also at a big party for Gershwin at the Trocadero on Sunset Boulevard, and he talked Russian to us."

Once the orchestra took Cecil B. DeMille's yacht to Mexico accompanied by Douglas Fairbanks Jr., Laurence Olivier and Robert Montgomery, who put on Russian smocks and insisted on joining in.

"They didn't know the Russian, so they would wait for the 'Hey!' that ends the refrain in a lot of Russian songs. Then they'd all shout it."

Twice Titoff played solo at Carnegie Hall. Stokowski was so excited about the rich tone of his contrabass balalaika--big as a bull fiddle--that he tried to work one into the Philadelphia Orchestra.

You can spot Titoff in 32 movies, either playing the balalaika or as an extra (once as a Cossack horseman). His pictures range from "Ninotchka" to "City Lights." He also toured for years in big-time vaudeville (hit New York three times) and made the Balalaika and Domra Association of America Hall of Fame.

The domra is a deep-bellied sort of mandolin, contrasting with the balalaika's severe triangular shape and three strings.

Slowing down just a little, Titoff (also sometimes billed as Titov or Grisha Gregory) worked nightclubs and ran his own party business as an entrepreneur who could summon up Serge Jaroff's Don Cossack chorus with a snap of his strong fingers. For six years, until the Mayflower was sold in 1972, he held forth at the Chatelaine Room with his group, serenaded Nixon and Humphrey (separately) and played for McGovern's daughter's wedding.

Then there were the Voice of America concerts and the great party in his apartment for members of the Moiseyev dance troupe in 1969. When he visited Russia the following year he got the red carpet treatment.

"We never talked politics," he says. "We wouldn't want to."

Probably not. The son of a bank treasurer in St. Petersburg, he fled Russia as a 16-year-old during the Revolution and spent his teen years in Harbin, that incredible Manchurian haven for white Russians. He moved to Seattle in 1923 and later to Hollywood.

"Then was when the life starts, really," he says. "I had learned balalaika from my older brother, a famous virtuoso, and it was my living."

His seven brothers and two sisters are all dead now, he says. Today, with his second wife and a grown son, he teaches balalaika and domra at home. Sometimes he takes out his Charlie Chaplin photo books and looks at the picture where he is that close to the comedian.

"Chaplin played the cello and violin, you know," Titoff muses, "but left-handed. Once we restrung a mandolin backwards for him . . ."