I've gone to endless trouble to find out whether Elvin Bale is in this year's visit of Ringling Brothers-Barnum and Bailey. He is.

As you've noticed, the big show will be playing four weeks in the area, at the D.C. Armory April 6 through 17 and at Capital Centre April 20 through May 1. The ads don't say which edition. Adding to the confusion is that RB-B&B is playing Baltimore's Civic Center through the 27th.Baltimore's is labeled "107th edition," is bound for Madison Square Garden and is known as the Red, or Gunther Gebel Williams, Unit.

Williams is the wild animal trainer and seems to get a lot more attention than Bale ever does in the buildup for ours, the 106th edition, or the Blue Unit.

For my money, Bale has it all over Williams when it comes to the circus thrills. He's the aerialist who works at the top of the arenas, at one point slipping to his heels above a swinging trapeze, at another racing along atop a 45-foot gyro wheel. Bale has nowhere to go but down. Williams can always run for it.

Bale is the cirbus equivalent of Robert Redford. His wife, Jeanette Williams (once married to Gunther Gebel Williams) is the daughter of the German Althoff circus family and appears herself with her Lipizzan stallions. Not since Lillian Leitzel has the circus had so chilling an act as Bale's. He's reason enough for our month of the Blue Unit. Though not so billed, Bale is a true circus star.

When it comes to "the show must go on" tradition, consider the situation of Liviu Ciulei, the Romanian director staging Gorki's "The Lower Depths" to play April 1-May 8 at Arena Stage. After word was flashed about the earthquake in Bucharest, Ciulei spend four days of uncertainty. When details filtered through, it was bad news. The theater he operates, Bulandra, and which was designed by his architect father 30 years ago, had been virtually destroyed and one of its leading actors was killed. "I wouldn't dream of going home," he told his cast, "we have a job to do here in rehearsals." Naturally, after the opening, Ciulei will be on the first plane home to see about how best to restore his shattered Buhcarest career.

Howard Keel's Florida success in "Shenandoah" has been noted by the Kennedy Center, which has booked Zev Bufman's production of the musical into the Opera House April 12-30. While "Shenandoah" had a brief run last summer at Wolf Trap, this will be its first D.C. run. Also in the cast are Barbara Marineau, Deborah Combs, Dennis Romer and Alan Jordan . . . The Center's Musical Theater Lab had a house-filled opening of "Hot Grog". In this experimental series the productions will not be riviewed, but tickets (freee) are available at the National Park Service desk in the Hall of States.

The 1976 Margo Jones Award for production of original scripts has gone to the Mark Taper Forum of Los Angeles and its artistic director, Gordon Davidson. In mid-April the theater will be celebrating its 10th anniversary, during which decade it has presented 17 new works among its 200 productions. The award is named for the Dallas, Texas, director whose theater was limited to new works.

The Folger Theater Group's next new play is "Black Elk Speaks," beginning previews Tuesday night. Christopher Sergel's drama is based on the nonfiction of John G. Neihardt and the cast is dominaed by actors from various Indian tribes; reservations at 546-4000 . . . Brecht's "In the Jungle of Cities" is scheduled to open on March 25 at ASTA Theater, 612 12th St. NW, playing Thursdays through Sundays; reservations at 628-8368.