"WE HAVEN'T lost a chorus yet," says James R. Bjorge, director of the fifth international choral festival of an amazing outfit called Choruses of the World.

Since he started 17 years ago at Lincoln Center, Bjorge has shepherded 75 choruses from 35 countries through an incredibly complicated program of tours and galas.

On Wednesday he will bring to the Kennedy Center university choruses from 10 countries and five continents, 400 strong, to sing both separately and en masse. They come from Quezon City, Philippines; Szczecin, Poland; Caracas, Venezuela; Lagos, Nigeria; Coventry, England; Strasbourg, France; Hamburg; Budapest; Yokohama; Ann Arbor, Mich.;Philadelphia and New Haven.

They'll all be in national costume, too.

The groups are met at the airport by special buses and whisked away on a three-week round of concerts at high schools, colleges and universities all over the East. They are put up by the colleges, the faculties and friends.

At various times during the tour they all converge for gala concerts: at Yale, Lincoln Center, the Kennedy Center and finally, in Philadelphia for the grand apotheosis with the Curtis Institute orchestra and the acclaimed choral conductor Robert Shaw, where they will perform Poulenc's "Gloria" and the "Ode to Joy" from Beethoven's Ninth Symphony.

Galas in the other cities will be accompanied by organ when necessary, but Philadelphia rates what Bjorge calls a world cantat because that city was the first to take on the project with money and other support, and this year it is celebrating its 300th anniversary.

At the local gala, each chorus will get about five minutes on its own, singing its traditional songs under its regular conductor. After the intermission, the whole group will come together to sing separately rehearsed numbers like "Gaudeamus Igitur" and Bruckner's "Ave Maria," winding up with a Japanese folk song and a Kodaly piece. Conducting this huge instrument will be Thomas Hilbish, director of choirs at the University of Michigan.

"It's also sort of an international festival for the conductors, too," Bjorge adds. "We pick the groups and their leaders very carefully. We almost never have the same one twice. The alumni conductors from those 75 choruses that already have sung in past festivals scout for us."

Supported by private contributions and help from the governments and communities and institutions involved, Choruses of the World goes back to 1931 when Marshall Bartholomew, then director of the famed Yale Glee Club, and 20 others founded the International Student Musical Council in Munich. After a slight delay caused by a depression and a world war, the idea got new impetus in the '60s, and finally William Schuman, Lincoln Center's president, gave the festival a home. The center is still active in the project.

What's it all about? It's about the joy of song, "the world singing together," as Bjorge says, the vast swell of human feeling that singing in chorus can bring even to people who haven't a word in common.

"Also, I like to think of it as a welcome to our ancestor countries. Without competition, you note. That's very important. If ever there was a moment in human history when we needed to bring people together rather than divide them, that moment is now."