Kate Reid and Joseph Sommer will play the mother and father in Robert Manson Myers' "Voices of Pride," which will open the Shakespeare & C. season June 9 in the Trapier Theater on the Washington Cathedral close.

Sommer has already had a hectic 1977. He was in the Pulitzer prize-winning "The Shadow Box" and left that for Arthur Miller's "The Archbishop's Celling," now at Eisenhower through May 28. Reids last appearance here was a Big Mama in the Eisenhower's "Cat on a Hot Tin Roof." Players of such rank as this for the intimate Trapier suggest that Ted Walch's company is moving into its most ambitious summer.

The author's "That Children of Pride" is the source for this story of a Georgia plantation family during the Civil War period and its aftermath. What a TV series that book could make!

Last summer the Reid-Sommer characters were seen in their youth, when John Gillis and Caroline Cromelin appeared in "The Courtship of Mary Jones." In this continuation of the story Gillis and Cromelin will be playing their own children. Also in the cast will be David Cromwell, now in the Folger's "A Midsummer Night's Dream." Reservations at 686-1733.

Olney's cast for its season-opener, "That Championship Season," will include David Snell, Bejamin Hess Slack, Robert Murch, John Capodoce and Herbert Voland. James D. Waring, in whose Catholic University classes author Jason Miller once was a student, will direct for a three-week run opening May 31, with a preview on Monday, May 30.Reservations at 924-3400.

A 14-foot high sculpture by Betty Klavun will be on the Marvin Center stage for the noval concerts labeled "Artucopia," dedicated to the National Endowment for the Arts by artists supposed by its grants. Friday and Saturday at 8 p.m. Mary Averett Seelye will perform her newest poetry-in-dance, drawn from T. S. Eliots "East Coker." Sunday at 7:30 p.m. the Contemporary Music Forum will include new works by Ulf Grahn and Lawrence Moss. Details at 381-7800.

"The Mamet Plays" - "Duck Variations" and "Sexual Perversity in Chicago" by David Mamet - opening tonight at 8 at the West End Theater, 23d and L Streets NW, will have novel weekend schdules, playing Fridays and Saturdays at 7:30 p.m. and 10:15 p.m. and SUnday afternoons at 3. Reservations at 296-2176.

The Musical Theatre Lab's next performances begin May 24 with "America," by Yoram Porat and Shlomo Gronieh, in the experimental space on the Kennedy Center roof terrace . . . "Happy Birthday, Black America," introduced last year by Grace Bradford, will be repeated Friday morning and afternoon at Woodson Senior High . . . Len Cariou repeats his New York role in Peter Handke's highly admired "A Sorrow Beyond Dreams" at Baltimore's Center Stage through May 29; reservations at (301)-332-0033 . . . Arena's Living Stage will be one of the companies performing at the New Theater Festival in Baltimore June 11-19, at 5401 Wilkens Ave; details at (301)-445-3193 . . . Arthur Miller's "The Crucible" will be directed by Jerry Whiddonfor the Street 70 Theater, opening May 27 at Rockville Civic Center.

Arena State's annual auction sets up its big top benefit Sunday, June 5, with a raft of novel chances, among them lunch with Marcel Marceau, another one with Rep. John Brademas (D-Ind.), a dinner at the Embassy of Egypt and a day in New York with soap opera's Victoria Wyndham; details at 554-9066.