PACIFIC CHORALE IN THE USSR. A special report : Estonians Sing Them a Different Tune : Music: The Pacific Chorale’s performance as part of Tallinn’s Festival of Oratorios and Cantatas is greeted with enthusiasm and understanding that the singers aren’t used to in Orange County.

It happened Monday night, after the Pacific Chorale’s first performance here as part of Tallinn’s Festival of Oratorios and Cantatas, one component of the first international Bridges of Song Festival.

The audience in Tallinn’s Kaarli Church did not come merely to pass the evening or out of curiosity about the first American professional choir ever to participate in the festival. Music--particularly singing--brings a sense of festivity and renewal to this city. When concerts appear, tickets disappear. The cavernous church was full.

They heard the chorale sing two pieces: Leonard Bernstein’s exuberant and hopeful “Chichester Psalms” and Herbert Howells’ requiem for his son, “Hymnus Paradisi.”

They listened with their ears and eyes. Looking down at them from the choral risers placed behind the Estonian State Symphony Orchestra and on either side of the altar, it was possible to see in the still-bright light of late evening their faces, full of earnest concentration, expectation and communion. This is a city and a people who obviously love beauty and harmony. At this crossroads in the often unhappy history of their Baltic republic, they seemed much in need of it.

The chorale singers were told beforehand that they should not expect applause. In an Estonian church, people do not express their appreciation with clapping hands or any overt show of sound.

But applaud they did. For more than five minutes and during five curtain calls. Here and there, some cheered. And when the choir filed off the risers and down church aisles, they were met by people who smiled, whose eyes teared and who nodded encouragingly.

It was the sort of intensely personal music-making that comes only rarely, if ever, when the chorale is at home: to look into the eyes of an audience, to see the music change their faces, to know that you have sung, and they have understood.

And now, Tallin is filling up with singers, many small ensembles from throughout Eastern and Western Europe--several appearing in native dress--and a handful from the United States who have come for the choral competition portion of the festival. Throughout the center of town, banners and posters announce the festivities with a tuxedoed green cartoon cricket holding a conductor’s baton. (To the chagrin of many Pacific Chorale members, cricket T-shirts are scarce).

While the chorale members have had little time to themselves so far for individual exploration--sightseeing excursions to outlying areas and rehearsals have occupied most daytime hours--they are beginning to feel more at home here with a few adjustments:

Pull the drapes at bedtime if you want to get to sleep. The sky gets dark only around midnight and never truly goes dim entirely. The sun comes up again, brightly, about three hours later.

Love the cucumber. It is served at every meal.

Breathe shallowly on heavily trafficked streets and in crowded rooms. Exhaust fumes from buses and tiny Lada cars and smoke from cigarettes can turn high A’s to gravel.

It is impossible to spend money. There are about 30 rubles to the dollar, and that will probably be enough to get you enough postcards, with postage, to send to everyone you ever knew in your life, or enough cut flowers to fill your hotel room.

Don’t stand in one place too long in the local department store. Wherever you are, a line will form behind you.

If you wear a jacket or sweater in the morning, you won’t need it by 10 a.m. If you don’t wear it, the weather will change and become frigid.

Don’t say too many nice things about the Russians.

Be prepared for the out of place event. After a tour of Tallinn’s Old Town, chorale members discovered what appeared to be a German Dixieland band playing “St. Louis Blues” in the market square. Television offers MTV, Bugs Bunny and years-old American car-chase dramas.

Be prepared to answer odd questions about the United States from passersby. (One young man, wearing a sweat suit, wanted to know the price of Nike shoes and a 5-year-old Chevy van, the dream of his young life. He also wanted to know if Rambo movies were a true reflection of American daily life and seemed skeptical when he was told they were not).

But it is, after all, the purpose of the Bridges of Song Festival to do what its name suggest: span cultural differences and explode myths. And so far, for one man at least, the Pacific Chorale has done away with one of them.

Outside of Kaarli Church after the chorale’s concert, many in the audience lingered to offer congratulations, chat and even solicit autographs from singers. One man approached Ginger Harms, an alto.

“He told me he always though that Americans didn’t know anything about good music and didn’t appreciate classical music,” said Harms. The man told her: “After tonight, I know that isn’t true.”