Tonight, a theater is born.

ASTA (American Society of Theater Arts) opens its house on the Hill. The first play is the Geoerge Kaufman/Marc Connelly farce about the silent flicks, "Merton of the Movies." It's an appropriate choice, for ASTA is rising on the ruins of the late Capitol Hill Cinema at 507 8th Street SE. It's as if the stage folks were saying farewell to the movies before replacing the shadows on the screen with live actors.

Underneath any tribute to the movies, however, partisans of live theater might gloat a little tonight as they watch Merton's disillusionment with Hollywood grow. What with the West End Theater turning to films after all those years as a stage, it was about time someone turned the tables. The movies we'll have with us always (I hope), but working stages are rarer commodities.

ASTA's old house was a little storefront at 612 12th Street NW. Seating as many as 60 people there required some squeezing, and stage space was limited. The new house will seat 140 before a stage that's about 25 feet square.

This may not be the Eisenhower Theater, but it's "lusciously ample" in the eyes of ASTA artistic director Dona Cooper.

It's also expensive. Multiply ASTA's rent at the old place - a dollar a year to the D.C. government - by more than a thousand and you come close to ASTA's new rent.

But Cooper thinks it's worth it. She expects the larger capacity to imporess funding sources and predicts that the location in a thriving residential community rather than in the dead of downtown after dark will attract new fans.

It's a gamble, but Cooper and company are not used to easy living. Most work other jobs during the day in order to support their theater. Cooper has a master's degree in theater but works as a secretary at the National Association of Automobile Manufacturers. Only the actors are paid, and they get a flat fee of about $100 per show.

"A lot of people were disappointed that we were leaving that quaint little space downtown," says Cooper, "but I could never begin to pay competitive wages there. And it loses its charm when you have to fight the water pipes and broken windows." Besides, eviction was only a matter of time. Those quaint low-rent buildings aren't expected to last long.

Still, let's sigh briefly for the ASTA theater that was. It and its remaining comrades offered the playgoer some physical adventure. Sometimes, as in the case of erratic heating or air conditioning, this isn't so pleasant. But it was fun not to know in advance how the seats were going to be arranged. The seats at the new ASTA are attached to the floor as they were for the movies, and the stage is a box that isn't going to allow much flexibility for breaking out of proscenium staging.

During a brief visit to the theater last weekend, not al the seats were installed yet. The departing movie people uprooted the chairs, and then ASTA bought them back, so they had sto re-installed. It was tempting to urge that they be left loose. However, it was pointed out that the audience might slide around the raked hall if the chairs weren't permanently attached.

Forsaking nostalgia, it's apparent that the new theater has plenty of advantages: a big lobby, a rehearsal hall that later can be converted into a second theater, a control room that overlooks both halls, and increased lighting space.

Cooper might not be around tonight. She has been hospitalized for tests. But from the hospital, she notes that ASTA has a 10-year lease on its new building. It plans to stay.