With its "Much Ado About Nothing" held over through Sunday, Jan. 22, the Folger Theater group does its duty by Shakespeare. Just ahead lie two new plays about today's Americans.

First of these is Jack Gilbooley's "Mummer's End," saluting Philadelphia's celebrated New Year's Day Mummers Parade.Part of the production, opening Feb. 4, will be film of last week's Broad Street happenings.

"Black Elk Speaks" will follow. This is a dramatization from the John G. Neihardt book by Christopher Sergel, relating history from the American Indian point of view. The cast will be comprised primarily of American Indian actors, some of whom have appeared in Cafe La Mama's Indian wing.

With such programming, new scripts and tested Shakespeare, the Folger group should inspire matching funds for its foundation "challenge grants."

Julie Harris's superb Emily Dickinson of "The Belle of Amherst," recently telecast, will be in the vicinity Jan. 31-Feb. 5. The performances are being sponsored by the Homewood campus of Johns Hopkins in Shirver hall auditorium. Details at (301)-338-7157.

Previews begin Friday for David Rabe's "Streamers" at the Kreeger, to run through Feb. 20. Continuing at New York's Lincoln Center, Arena's new Kreeger production is being staged by David Chambers. That is the third of the Rabe trilogy about the Vietnam War period, introduced by "the Basic Training of Pavlo Hummel" and "Sticks and Bones," Joining such regulars as Robert Proskey, Howard Witt and Michael Mertz will be Damien Leake, Joel Colodner, Terry O'Quinn and Brent Jennings. Producer Zelda Fichandler warns: "Because of its vivid depiction of violence and language, 'Streamers' is not recommended for children."

Alexander H. Cohen, overseeing "Hellzapoppin" repairs in Boston, won't have the same script problems with his next play, O'Beill's "Anna Christie." This will star Liv Ullman, with John Lithgow as the sailor. Robert Denley as her father and Mary McCarthy as the old lady Marie Dressler played so vividly in the Garbo film version. This will be along at the National for four weeks starting March 14.

Costumer for "Anna Christie" will by Joan Greenwood, who did the same for the current "Otherwise engaged" at the National and "Caesar and Cleopatra," starting previews Friday at the Opera House. In the "Caesar" cast is Patrick Hines, the barman of "A Texas Trilogy," for which Miss G. did the costumes. Also in "Caesar" is Paul Hecht, who took over as the strolling player in "Rosencrantz and Guildenstern Are Dead," which costarred John Wood. Wood is opening tonight at the Eisenhower in "Travesties." In theater everyone is related through some production-in-common. Small world.

The Paul Robeson Multi-Media Center resumes with previews tonight through Sunday of "The Sirens," by Richard Wesley. The story of three women and two men deals with a young woman forced into prostitution to feed her young baby after her husband band deserts her, St. Clair Christmas directs a cast which includes Esther Anglade, Kashka, Richard Ponds, Sandra Bowie and Cheryl Johnson; performances will be Thursday through Sundays; details at 232-3554.

Baltimore's Center Stage is playing Shaw's "Misalliance" through Jan. 30 under the direction of Arne Zaslove. Among the players: Christine Baranski, Dan Diggles, Davis Hall and Paul C. Thomas.

"American Yarn . . . Tall Tales America Grew By" begins a series of Saturday performances for Street 70's Theater Company on Jan. 22 at the Rockville Civic Center.

Andy Griffith is headed for his native North Carolina to emcee its Inaugural Ball honoring Gov.-elect and Mrs. James B. Hunt Jr. Friday night in Raleigh. The actor made his bow in the state's "The Lost Colony" and never fails to support its progressive arts alignments . . . . Rodgers and Hart have changed the sometime iffy winter season for the Harlequin Dinner Theater, where "The Boys From Syracuse" has been extended through Feb. 6 . . . Melba Moore, bringing her Metropolitan Opera House concert to Baltimore's Civic Center on Feb. 12 (Lincoln's birthday), introduces to the area a new concert management, "Lady L. Production." The anonymous "Lady L" promises she has more productions to come. . . . In-the-Works is the title of a new monthly newsletter about arts in the area sponsored by the Washington Artists Congress; details at 546-4319. . . . Washington actor Richard Kavanaugh has a lead in Jules Feiffer's "Knock Knock" at the Providence Trinity Square Rep., which now moves to Boston's Charles Playhouse.