Once again, the Vienna Choir Boys proves to America that you don't have to scream raucously, scrape your voice and be amplified to eardrum-splitting proportions to draw a crowd.

No indeed; a capacity audience filled Symphony Hall last night to hear the sound of boy soprano, a gift that comes to only a few - an ethereal sound that's infinitely precious, as fleeting as the few tender years when boys' voices can produce it.Though the boys change every year, "boy soprano-ness" never does. It's a state of being, an embodiment of innocence, whose naivete and Old-Worldly charm keep an audience coming back to hear these voices, as pure and clear as spring water, singing with a sweetness that never disappoints.

That said, I must confess that I've heard stronger and more confident editions of the Vienna Boys Choir. Though their discipline is such that they never give in, they sounded perhaps a little fatigued, especially in the operetta, and one suspected that a few colds were bothering them.

Nor was (American) English pronunciation a strong point. Since they sing the operetta songs in German and give the dialogue in English, usually you can keep up with the story. But this time the dialect was clipped, the voices often soft and heads sometimes turned away from the audience, so that you couldn't make out much of what was going on.

For America, the boys need to adopt a more American dialect or have amplification so that you can at least clearly hear their accented words and have a fighting chance to make out what they are saying.

However, understanding may not have been too significant, since "Old Vienna" seemed to have the flimsiest of plots, about people enjoying themselves in the park with flirtations in three-quarter time.

There was a "leading lady" who sang beautifully, a number of other good little soloists, and one who seemed on the edge of voice change. Nonetheless, the operetta was as always a delight, showing off the youngsters' acting ability, boyish charm and high spirits.

The chorus opened with selections from Britten's "Ceremony of Carols," written originally for boys' choir. It was done pleasantly enough, with some pretty solo passages. The "Wolcom Yole" rang out brightly, and the slow, lullaby pieces were smoothly sung.

But again, words were not clearly articulated, and in "This Little Babe" the canonic interplay got lost in the shuffle. Also the piano was sometimes too loud, as it tended to be at times all evening.

Dependable musicianship is a high point with these children, and balanced programming that offers always some familiar songs, along with others you never knew and wish you had. Especially lovely was "Die Engel und Die Hirten," an unaccompanied canonic anthem with modern harmonies, by Zoltan Kodaly.

Solo numbers by Mozart - a two-part concert song showing fluent technique, and one of the boys' trios from "The Magic Flute," which made one long for so good and authentic a trio in every production of the opera - showed off individual artistry and fine vocal production.

A waltz of a different sort was Elgar's "The Dance," a substantial piece of music in the English mode. This and a delightful set of childhood songs by Poulenc - "The Good Little Girl," "The Lost Dog," "The Hedgehog" colored with his special felicity in writing for the voice - comprised an interesting English group. Again, better if one could have more clearly discerned the words.

Turning to German folk songs, the choir was in its element for some expressive, charming singing, among the most enjoyable of the evening. The concluding "Blue Danube Waltz" was as always a delight, followed by a couple of encores including "Bury Me Not on the Lone Prairie," in which no word was missed as the playful pianist gave out with some twangy Western swing.

- Leonard Bernstein decided two weeks before he died to use a $100,000 arts award he had won to further musical education. He was honored posthumously in Tokyo with a Praemium Imperiale award, which will be used to establish the Bernstein Education Through the Arts Fund.

"The Bernstein Fund will be one of many lasting legacies left behind by this towering figure of 20th century culture," said Hiroaki Shikanai, chairman of the Japan Art Association's Praemium Imperiale executive committee. "We are touched profoundly by Mr. Bernstein's generosity and his commitment to a significant role for the arts in modern society."