The Choral Arts Society presented the first of its three big Christmas concerts Sunday night at the Kennedy Center. The group, 180 strong, performed massed readings of the Giovanni Gabrieli motet "Hodie Christus Natus Est" and Bach's "Gloria in Excelsis Deo." On the more intimate side were four European carols, performed by a smaller group in each of the four official languages of Switzerland, including Romansch.

The level of execution ranged from the competent through the capable and committed. The evening profited from Music Director Norman Scribner's bold, extroverted approach and his special way of shaping sound that seems firm, never mushy. Indeed, such a jamboree inevitably loses something in the Concert Hall, which is not reverberant like a cathedral. But the theatrical fanfare of Richard Wayne Dirksen's "Welcome, All Wonders" could not fail to produce a very grand effect. Contributing to both musical quality and sheer sound-mass was a good-sized orchestra consisting of many National Symphony Orchestra musicians.

There was a brief but shining moment for the silken-voiced tenor Robert Petillo, who sang a duet with soprano Rosa Lamoreaux in the Bach. He is certainly someone to watch.

In "Carols for Everyone," no coaxing was needed to get the audience onto its feet and singing. A small asterisk next to tunes like "O Come All Ye Faithful" got the message across. In tunes reserved for the onstage chorus, a few eager patrons started to sing, dropping out when they noticed the absence of an asterisk. This created a curious variety of staggered dynamics in "Deck the Halls."

The Christmas music program repeats on Friday and Sunday.