Whenever I have gone to hear the Alexandria Choral Society, which is as often as circumstances permit, it has always been in a church--usually in Virginia, once in Georgetown--whether the music is religious or not.

This, I suspect, is a matter of economics. The Alexandria Choral Society is not one of the big Washington choruses that can afford to rent an auditorium in the Kennedy Center, as many of those choruses will be doing between now and Christmas.

Churches, which have lots of seats and offer them to worthy organizations at little or no expense, are literally the salvation of some of Washington's finest musical organizations.

I think of Epiphany and St. John's, which are hosts to the Washington Bach Consort each month; Temple Emanuel in Bethesda, which has its own concert series; Western Presbyterian, which previously hosted the Washington Men's Camerata and will host the first concert of the new National Men's Chorus on Dec. 5; Bradley Hills Presbyterian, which offers the use of its handsome and acoustically excellent sanctuary to a variety of groups; and others too numerous to list. These churches touch the souls of many who have never gone there to hear a sermon.

But for its concert on Saturday night, opening its 30th anniversary season, the Alexandria Choral Society moved into the Kennedy Center's Terrace Theater for a one-night stand.

This is, apparently, something it can afford to do every 10 years; it made its Kennedy Center debut 10 years ago while celebrating its 20th anniversary.

One reason this chorus does not appear in Washington more often, of course, is that it lives in Alexandria, a city with its own distinctive identity, now celebrating its 250th anniversary and entitled (if it were not so scrupulously polite) to dismiss Washington as a Johnny-come-lately. But money is clearly part of the equation.

The Alexandria Choral Society is less affluent partly because it is small--about 50 voices.

Big choruses attract big audiences because many people like a big sound in a big hall, but also because chorus members have friends, relatives and business associates who are interested in hearing Uncle Charlie (or good old Charlie) sing Brahms or Handel or Mendelssohn along with a few hundred others.

It is also less affluent because it is noted for adventurous programming--music that is not often heard. Its specialty (though it does other things, too) is American music--something that American audiences try to avoid, though American music does quite well in Europe, as the Alexandria Choral Society has learned on its eight European tours since 1990.

A special interest in American music, and particularly the music of Virginia composers, is highly appropriate for one of the most important musical organizations in a Virginia city that is proud of its heritage. A significant part of the society's budget is spent on commissioning new music--a new piece about every two years since 1984.

All of these themes blended in Saturday's Terrace Theater concert, titled "American Classics Old and New." It was conducted by Kerry Krebill, who became the chorus's music director in the 1980s and has since developed its distinctive flavor.

The first half of the program was devoted to modern composers, most from the Washington area, including the world premiere of "Songs of Mystic Love" by James Grant, with texts by St. John of the Cross; settings of two of John Donne's sonnets by Williametta Spencer and the late Russell Woolen; and "No. 10/Supreme Virtue" by Mark Adamo, with a text from the Tao Te Ching.

The second half of the program was devoted to older music by William Billings, Charles Ives, William Hawley and Aaron Copland.

Unlike some of the group's concerts in churches, this one was devoted entirely to religious music, and it was performed with a clarity, balance and devoted attention to the words that did full justice to the music.