"Old World" has been retitled "Do You Turn Somersaults?" - but people still think of it sas "the Mary Martin play." Actually Anthony Quayle also stars in this two-character comedy now rehearsing in New York for a six-week run at the Eisenhower starting Aug. 18.

The author is Aleksei Arbuzov and originally it was titled "Staromodnaya Komediya," translated as "Old Fashioned Comedy." The new title is a line in this story about a mature doctor and a circus performer who meet in a health resort in Riga. Arbuzov is the author of "The Promise," which I reviewed a successful London run but failed in America, probably because accents of an English cast suggested this three-character piece about World War II had a British setting.

This is not a musical, though it does allow the musical star to sing or him snatches of a circus waltz theme by Charles Gross.

Edwin Sherin is directing the Ariadne Nicolaeff translation. After it is launched in New York, Sherin turns to "First Monday in October," the Jerome Lawrence-Robert E. Lee play about a woman on the Supreme Court, opening in December at the Eisenhower. Its stars will be Jame Alexander (Mrs. Sherin) and Henry Fonda.

Rock Hudson's stand-up ovation from a Shady Grove audience - which have overflowed the Kennedy Center's Opera House - was, in a sense, a tribute to him, for he'd "sung" "Camelot's King Arthur with a cold as heavy as the FBI building. His companions are exceptional professionals. Jerry Lanning, the Lancelot and Roberta Sherwood's on, is the best of recent "Show Boat" Revenals. Hudson spent yesterday afternoon with a doctor from the audience, confident he'll override the cold.

Helen O'Connell, who introduced "Green Eyes" and "Tangerine," stars with Bob Eberly and Tex Beneke's "Big Band," holding over Wednesday at Wolf Trap after a Tuesday night opening. Scratch England Dan and John Ford Coley from the Wednesday schedule.

SOURCE, a new theater company member of the Washington Project for the Arts, makes its bow Wednesday in Synge's one-act drama of the Irish coast's Aran, "Riders to the Sea." Under the direction of Bart Whiteman performances will be at 8 and 9:45 throught July 29 at 1227 G St. NW; reservations at 347-8304.

"Mojo," by Alice Childress, and "Herbert III," a comedy by Ted Shine, form a double bill playing Fridays through Sundays through July 31 at Back Allley Studio, 617 F St. NW, produced by Minority Arts Ensemble; reservations at 387-1875.

Roger Meersman, director of the Sylvan Theater's "Romeo and Juliet," joins producer Ellie Chamberlain and Wayne Richardson in a discussion of Shakespearean acting styles at Wednesday noon's Kennedy Center symposium in the AFI theater.

Annandale's Payla Schwartz will see her new three-act play, "Afterwords," next week in the Barter Theater's Works-in-Progress series . . . "Butterflies Are Free" joins the repertory of Charlottesville's Virginia Players this week . . . "Once Upon a Mattress" is the bill through July 31 at the Wayside Theater, Middletown, Va. . . . Norfolk's new-old Colonial Theater, now the Corinthian, has put off its opening as a legit house until Aug. 13 and 14, when two plays, "Peace Without Victory" on Saturday, and "My Eldest Son" on Sunday, will start a new life off Granby Mall . . . Wolf Trap children's theater thrives. In the Meadow Tent, Interplay Productions presents "Happy Landings" at 10 and 11 a.m.; at Theater-in-the Woods, the Bob Brown [WORD ILLEGIBLE] reveal "The Art of Puppetry II" at 10:30 a.m. and Archaesus presents "Encore" afternoons at 1:30 . . . Montgomery County's Street 70 presents "Hello, Dolly" next Thursday at Rockville Civic Center, with repeats through Aug. 7 Details at 463-4172.