The climax of last night's concert in the Shrine of the Immaculate Conception was the Berlioz "Te Deum," a work that is especially comfortable in the vast spaces of the great church.

However, it is hard not to think that the most beautiful music of the evening came at the very beginning when Robert Shafer led an orchestra of strings in Samuel Barber's "Adagio." Seated in a semi-circle in front of the main altar, the strings were lent a radiance by the way their tone spread through the shrine. It was a unique aural beauty in a moving performance.

The 450 singers of the Oratorio Society, McLean High School Choir and a children's choir moved into place behind the orchestra while organist Robert Grogan played the Franck "Piece Heroique."

Then, with Grogan playing the large organ in the east gallery in excellent synchronization with his massed singers and players in the front of the church, Shafer led an imposing account of the "Te Deum." Its tempos are chiefly on the slow side, which means that it works well in the reverberant spaces. But it is also related to the fact, or may even be the reason why Berloiz is at a loss for fresh ideas. A considerable amount of the music sounds as if he were getting himself ready for a major pronouncement. Only the pronouncement comes too late, and is, finally, not enough.

The great effects are impressive, the orchestral writing full of imagination and the tenor solo at "Te ergo quaesumus," sung with real elegance by Gene Tucker, poetic. The chorus was expert at every point, and Shafer had the huge project well in hand.