Look for dividends this summer once Shady Grove Music Theater opens its season May 3 with Gladys Knight and the Pips.

On the broad circular terrace there will be young performers, sculpture picnic tables and chairs, food stands, and soft drinks, an informal all acts adventure to start each evening around 6:30, weather permitting. Also painting exhibits in the inside lobby will feature area artists.

This concept is that of David Kanter, newly appointed managing director of Shady Grove. Kanter, who recently retired from Temple University Music Festival, which he founded 10 years ago, hopes the schedule will allow him to produce one of the Gian Carlo Menotti operas with which he's been a production associate since their creation.

Specialty performers will dominate Shady Grove's schedule but at least two musicals are assured, Roberta Peters in "The Merry Widow" the week of July 5 and Rock Hudson as King Arthur in "Camelot" the wek of July 19.

With Cloris Leachman and Paul Michael Glaser, of the TV hits, as Sunday night's special guests for the Irene Ryan Evening of Scenes, the Kennedy Center's American College Theater Festival also includes a special symposium next Wednesday at noon in the AFI Theater.

"Buidling the Arts into the General Education program" is the title of this discussion to be led by the Vice President's arts-conscious wife, Joan Mondale, with Illinois State's Cal Printer; George Moran, author of UCLA's "Upstream Towards Lethe"; and two local critics on the panel.

"Lear", presented by the University of Alabama, Tuscaloosa, will be repeated today at 2 p.m. and 8 p.m. in the Eisenhower, with Coward's "Hay Fever" by Webster College, St Louis playing Friday and Saturday.

Gig Young has withdrawn from one of the starring roles of Arthur Haler's "The arch bishop's Ceiling" and will be [WORD ILLEGIBLE] by Douglass Watsoir in the Elsenhower-bound drama . . . [WORD ILLEGIBLE] Jonny Holiday draws the role of Adam Mark Twain's Adam as one of his three parts in "The Apple Tree," the muscial which begins a preview run tonight at Harlequin Dinner Theater . . . For a time it looked as though Lily Tomltn's sole revuene "Appearing Nitely" would make it to the National, but her New York success will keep her there till its filming time on the coast . . . Theodore Bikel, Equity's multi-talented president, and David Bar-llan, the Israeli pianist, will perform May 1 at Silver Spring's United Synagogue of America; details at 434-6650 . . . That's the same night Betty Comden and Adolph Green will do their current Broadway revenue to benefit Arena Stage's sustaining fund; for that one, call 554-7890.

Back Alley's "Short Eyes" last night gave a special performance at Lorton . . . Hexagon's "Jest a Minute" will have a performance tonight at the nation Press Club . . . Georgetwon classical Theater, the University's Shakespearean ensemble, is continuing "The Merchant of Venice" through Tuesday at Stage Three, 37th and P Streets N.W., at 8 p.m. . . . Though a professional touring company has been playing "Jesus Christ, Superstar" in Baltimore, the University of Maryland's College Park campus isn't worried about comparisons with its version, which opens on April 14. Director-critic Roger Meersman is wholly conflident his cast of 60 will be far superior . . . Olney has set its opening date for May 31, but the play is undecided. One thing is cetain. There will be an Agatha Christie . . . Elvis Presley has a date at Capital Centre may 22, a Sunday at 9 p.m.: seats go on sale Friday. This Friday, 10 a.m.