The theatergoing pack will rush right by this one: a pair of Tennessee Williams one-act plays at d.c. space, presented by the Spheres Theater Company.

There is barely room for 50 people in the upstairs homemade theater at 7th and E streets NW (Gallery Place on the Metro), and the whole evening lasts about 70 minutes. But it is a lovely reminder that quality is not, after all, the same as quantity. We tend to forget, these days.

The first play, "A Perfect Analysis Given by a Parrot," is bright and quick -- and funny. It is a short story. It is Saroyan with vinegar. Two women, camp followers with a veterans' convention, almost reveal themselves in the unguarded intimacies of old friendship. It ends abruptly in hilarity, but the pain one always feels with Williams is there just the same.

The second playlet, "Portrait of a Madonna," written in 1945, appears to be a study for "A Streetcar Named Desire," which came two years later. The basic character prototypes are there, in Miss Lucretia Collins, fey, lost and on her way to the mental hospital, and the Elevator Boy, vulgar, vital and sexy.

All of Williams' plays are so bursting-out with sexual tensions that they remind one of a cat dressed up in doll clothes. In this case it's a tiger.

Another Williams specialty is the rich part for a woman. Here, Marilyn Kray takes over as Miss Collins, dabbing her thoat with drops of water, dreaming of the past, utterly dominating the small stage without effort.

At the climax she tells a long, vague story. It hardly holds us, murmured as it is. Then the Elevator Boy puts on an old record: Ravel's "Pavane for a Dead Infanta." Suddenly everything comes together, and you realize what she is saying, and the audience forgets to breathe, and there is no sound in the room but that small voice. Maybe it is pushing things just a bit to bring on the wonderful, grave music, so moving, so infallibly evoking the past. But still, this is one of those moments that you come to the theater hoping to find, year after year. You never can tell when it will happen, or where.

The plays will continue nightly at 8 through july 20.