For something conceived on a whim at a party in a Moscow apartment less than a year and a half ago, it is surprising how much of an expatriate institution the Moscow Oratorio has become with its Christmastime performances of Handel's "Messiah."


"Some of the sort of pre-Christmas spirit that exists elsewhere in the world has always been lacking in Moscow," said Andrew Sparke, a Briton who helped start the expatriate choral group last year with Helen Womack, a British journalist. "You sort of feel like we are missing something here -- the caroling on the streets, the people dressed like Santa Claus, the window displays."


When the amateur singing group performed the "Messiah" on Dec. 10 and 11, some 800 people attended the benefit concert at the Radisson-Slavjanskaya Hotel. That's a long way from the Oratorio's humble beginnings in August 1993 at a farewell party for a Moscow journalist.


"Helen Womack and I went to a party, and we got talking and found a mutual interest in music, said Sparke, the project manager for a Russian-language soap opera produced by the British Broadcasting Corporation. "And we thought, 'Wouldn't it be interesting to do a performance of the 'Messiah'?' She would do the alto solos, and I would conduct."


Sparke was the conductor last year, but now no longer participates. Still, the Moscow Oratorio is going strong with a new generation of singers.


One new member, Pam Jordan, a doctoral student from the University of Toronto, has been in Moscow for two months. She said she was grateful for the choir's existence.


"I'm not going home for the holidays, so it gave me something to do," said Jordan before a rehearsal. "It gives me that spirit that I might not ordinarily have because I spend so much time researching."


Made up of expatriates from all over the English-speaking world, the Moscow Oratorio has a high turnover -- which the group's current choral director, Irina Walters, said is a challenge.


"You never know who will be in the choir tomorrow," said Walters, who is paid to conduct the 40 or so regular members of the chorus and the accompanying orchestra. "It is typical for amateur choirs, anyway."


Walters, who recently graduated from Moscow's Tchaikovsky Conservatory with a degree in conducting, said she finds leading the amateur expatriates preferable to working with paid professional singers.


"In a professional chorus, they don't take your word for granted, and they are very competitive," she said. "They trust your professionalism much more in an amateur chorus. With an amateur choir, you are using more of your soul. It is more of a fairy tale."


Members of the Moscow Oratorio paid about $20 each to cover some expenses. Oratorio treasurer Lisa Heyden said the concert itself was performed as a benefit, whose yet-to-be-tallied proceeds will go to Novy Dom, a Russian charity working with Moscow's homeless people.


Mike Lonneke, the general director of Radio 7 and a bass in the chorus, explained the strength of the group's appeal.


"It is a thrill to be with other singers who are like-minded with this art music," said Lonneke. "It is not that we don't like pop music too. But this music has a special soul to it. It is the thrill of being associated with a great work of art."