The wonder is not that flutist James Galway played so beautifully at the Kennedy Center Concert Hall Saturday night.Most assuredly he did -- and he was expected to do so.

No, the wonder is that his virtuosity and personality did not dominate the stage he shared with harpist Marisa Robles and violist Milton Thomas. They could match him note for note, quip for quip and phrase for phrase. The wonder is that they could assemble a delightful program for that unlikely combination, could establish an instant mood of informality and bonhomie in that rather impersonal and formal hall, and then proceed to the highest levels of musicmaking.

Galway is already a legend. He is as ubiquitous on TV talks shows as he is in the concert hall and on records and tapes, and he has a marvelous ability to bring the audience with him. Kennedy Center Concert Hall audiences rarely laugh. They are wont to sit solemnly and almost ritually through the wittiest music, as if daring a composer even to make them smile.

On Saturday under the ministrations of the trio, listeners unbent just a bit, giggled a little and even clapped occasionally in forbidden places (although shushed by more righteous cognoscenti).

The program brought together an assortment of pieces written for this combination and some successful arrangements. Everything was delightful, but Thomas' performance of a Bach Choral Prelude, phrased with exquisite beauty; Galway's spectacular performance of a CPE Bach Sonota; and Robles' splendid elan in a most harpistic piece by Hasselmans were particularly so.