Quick! Here's a spot quiz on summer theater:

Summer theater is:

a. Watching "Barefoot in the Park," barefoot, in the park.

b. Watching the girls/boys go by, from the best seat at a sidewalk cafe.

c. Everything from Shakespeare to Shaw to Larry Shue.

d. All of the above.

The answer, of course is "all of the above" and more -- summer theater has evolved so far beyond the "straw hat circuit" that it really can't be neatly labeled anymore. That's evidenced by the offerings up and down the East Coast. Here's a sampling of summer stock and festivals, within driving distance of Our Town: MARYLAND

OLNEY THEATER -- Our near and dear neighbor was the first summer theater south of the Mason-Dixon Line, and it's become a venerable Washington summer tradition. The season: "The Foreigner," now through July 7; "Painting Churches," July 9 to August 4; "The Miss Firecracker Contest," August 6 to September 1. Make sure you make time to eat at the Olney Ale House across the street. About 15 miles from D.C. on Rt. 108 in Olney, Md. Call 924-3400.

BALTIMORE "ON STAGE DOWNTOWN" -- From July 11 to August 29, Baltimore's many community and dinner theaters present outdoor performances of their current shows, free to the public. The lineup: July 11, "Tom Sawyer" by The Court Jesters; July 18, "Goodbye Blues" by Arena Players; July 25, "Viva Broadway" by Baltimore Actors Theater; August 1, "Guys and Dolls" by Fells Point Dinner Theater; August 8, "Brigadoon" by Liberty Showcase Theater; August 15, "The Music Man" by Colony 7 Dinner Theater; August 22, "Camelot" by Cockpit in Court; August 27, "The Pirates of Penzance," by the Hadley Square Singers. Performances are at 8 p.m. at Hopkins Plaza, between Baltimore and Lombard Streets. Call 301/837-INFO.

ORE HARBORSIDE THEATER -- Every Saturday evening at 8:15, Baltimore area troupes will perform the best of Broadway musicals. The theater, designed to resemble the interior of a clipper ship, is at Rash Field near the Inner Harbor. And from June 29 to July 13, at 8:15 p.m, "H.M.S. Pinafore" is performed by the Young Victorian Theater Company, Baltimore's resident Gilbert & Sullivan troupe. 301/625-1400 to order tickets, 301/837-INFO for info.

THE MARYLAND SHAKESPEARE FESTIVAL -- Debut of a new summer theater series in St. Mary's City, the festival opens with "As You Like It," now through July 7; followed by Moliere's farce "Scapino," July 12 to 28. Living history productions are presented on Saturday and Sunday afternoons through August 4. The outdoor stage has a lovely view of the St. Mary's River, right down the hill from the reconstructed State House. 90 minutes from D.C. 301/863-5767.

WILDWOOD SUMMER THEATER -- This is the all-teenage theater troupe's 22nd year; Jonathan Hadary, star of Broadway's "As Is," is one of the group's founders. They're doing "Fiddler on the Roof," July 25 to 27, August 1 to 3 and August 8 to 10, 8 p.m. Tickets are $5; performances at Walter Johnson High School Auditorium, 6400 Rock Spring Dr., Bethesda. Call 897-9630.

ROCKVILLE MUSICAL THEATER -- The troupe's 11th annual summer show is "The Robber Bridegroom," described as a "bluegrass love story," July 5 to 27 at F. Scott Fitzgerald Theater, Edmonston Drive and Baltimore Road, Rockville. Call 942-5005.

THE CASTLE -- This brand new performing arts center, reclaimed from the old Hyattsville Armory, opens this Friday at 8 p.m. with an introductory summer season, featuring Martin Mangold's new opera "Huckleberry Finn," directed by artistic director Antoni Sadlak/Jawoski. It plays through July 7, followed by "Grease," July 18 to August 17. 5340 Baltimore Ave., Hyattsville. Call 301/277-6121. VIRGINIA

ROCK KILN RUIN -- This is the second season for this new under-the-stars theater, a natural amphitheater created from an abandoned kiln. Associate producer Josephine E. Ayers says the company's work is "rooted in the history and heritage of the people of the southern mountain region," and promises "spectacle, cannons and ghosts," which should be enhanced by the outdoor environment. The season is on a repertory schedule, so if you go for the weekend, you can see all three shows: July 19 to August 25, "Stonewall Country," world premiere of an original musical based on the life of Stonewall Jackson, with music written and performed by Robin and Linda Williams; July 23 to August 23, "Rock Kiln Ruin's Tale of Cymbeline," a country-tinged adaptation of Shakespeare's comedy; July 21 to 24. "Red Fox/Second Hangin'," about the Virginia frontier. Bring a sweater and a picnic. About three hours from D.C. in Lexington, Va. Call 703/463-3074 for directions and details.

WAYSIDE SUMMER THEATER -- This summer stock company has been entertaining Civil War-historic Middletown for 26 years. Wayside opened this season with "Barefoot in the Park," and their version of "The Innocents," an adaptation of Henry James' "The Turn of the Screw" ends June 29. Still to come: producing director C. Edward Steele in his one-man show "Mark Twain Himself," July 3, 5 and 6; a vaudeville version of "A Funny Thing Happened on the Way to the Forum," July 10 to 20; "Tribute," July 24 to August 3; "Crimes of the Heart," August 7 to 17; "Private Lives," August 21 to 31. The theater is about 90 minutes from D.C., on Rte. 11 in Middletown. Call 703/869-1776.

LUBBER RUN AMPHITHEATER -- Arlington's pleasant outdoor stage is filled with the sounds of music for most of the summer, but theatrical offerings include the Children's Theater of Arlington's "The Magical Pied Piper" June 28 to 30 and July 5 to 7; followed by the Arlington Players' annual community- casted summer production, Stephen Sondheim's "Company" this year, August 9 to 11, 16 to 18. Call 558-2165.

VIRGINIA SHAKESPEARE FESTIVAL -- The Festival's four-play repertory season, July 4 to August 17, includes "The Taming of the Shrew," "Richard II," Moliere's "The Miser" and "Cymbeline." Performances are in the Phi Beta Kappa Memorial Hall at the College of William and Mary, Williamsburg, about a three-hour drive from D.C. Call 804/253-4469 for schedule and reservations.

LITTLE THEATER OF ALEXANDRIA -- This troupe, which is noted for its touch with colonial plays, begins its second 50 years with the bicentennial musical "1776." ("We're very good at doing '1776,' says a Little Theater volunteer. "We should be -- we've done it twice, in 1976 and '77.") The show runs July 19 to August 10, at 600 Wolfe St., Alexandria. Call 683-0496. DELAWARE

REHOBOTH SUMMER THEATER -- A recent addition to the Rehoboth beach scene, the summer theater is presented by the Rehoboth Art League in a large open room with lots of windows. The season: July 22 and 23, 8 p.m., world premiere of "The Winter Man" by Irish playwright Neill Montgomery; plus Samuel Beckett's "Texts for Nothing." August 19 and 20, 8 p.m.: "Jacques Brel Is Alive and Well and Living in Paris." 12 Dodds Lane, Henlopen Acres in Rehoboth Beach, Delaware. Free parking, restaurants nearby. 302/227-8408. PENNSYLVANIA

TOTEM POLE PLAYHOUSE -- "The best-kept secret in Southern Pennsylvania," the Totem Pole was operated for 30 years by Jean Stapleton and her husband William Putch, who always employed plenty of Washington- Baltimore actors. Now it's run by Catholic University alumnus Carl Schurr, who is executive producer and artistic director and plans to carry on the tradition. The season: June 18 to 30, "See How They Run"; July 2 to 14, "Night Must Fall"; July 16 to August 4, "A Funny Thing Happened on the Way to the Forum"; August 6 to 18 "Foxfire"; August 20 to September 1, "Sa Time Next Year." At Caledonia Stage Park in Fayetteville, it's less than two hours from D.C., 12 miles west of Gettysburg, with lots of Civil War-iana nearby, antiquing and other vacation-type stuff. Call 717/352-2164.

AMERICAN MUSIC THEATER FESTIVAL -- Philadelphia hosts the second annual month-long festival, which features a total of 101 music theater events from September 12 to October 13 at the Annenberg Center of the University of Pennsylvania. The five feature productions include "SEEHEAR" by George Coates Performance Works; "Mowgli," an adaptation of Kipling's "Jungle Book," directed by Tom O'Horgan; a new staging of "The Gospel at Colonus"; and two premieres to be announced. Call the Festival Hotline, 215/988-9055.

AMERICAN SHAW FESTIVAL -- The only Shaw Festival in the U.S., this international company is located about 21/2 hours from D.C. The summer season (called "A Summer Celebration of Independence: Shavian and Otherwise") includes a world premiere of a new version of Ibsen's "A Doll's House," now through July 6; a free drama/comedy/music revue called "Celebration of America" on July 4; "A Shavian Sextet & A Cowardly Duet," a pastiche of Shaw and Noel Coward work, July 9 to 20; Carol Teitel's "Faces of Love," which draws from theatrical women in Shaw, Williams, Joyce and others, July 23 to 27; Shaw's "Pygmalion," July 30 to August 10; and Tina Howe's "Painting Churches," August 13 to 17, plus Monday one-nighters like "St. Joan: An Epilogue," a comedy called "Hello, Dali" and more. Performances are at historic Mount Gretna Playhouse in Mount Gretna. Call 717/964-3627 for complete schedule and directions. NEW YORK

NEW YORK SHAKESPEARE FESTIVAL -- Now we're getting a bit far afield, but birthdays merit special attention, and a lot of us seem to pass through here: Central Park's Delacorte Theater (called "Papp Trap" by some Washington wags) is the site of the 30th anniversary performances of producer/director Joe Papp's free Shakespeare Festival. Set by Papp in 1910 Vienna, "Measure for Measure" (Tuesdays through Sundays through July 21) is Shakespeare's darkest comedy of sex and politics, and the cast includes Washington actor Steven Dawn, who recently won the first Helen Hayes Award for best supporting actor. On August 2, the world premiere of pop composer Rupert Holmes' new musical "The Mystery of Edwin Drood," based on Charles Dickens' unfinished novel, stars George Rose, Betty Buckley and Cleo Laine, Tuesdays through Sundays, through September 1. Tickets are distributed each night at 6:30 p.m. at the Delacorte Theater on a first-come first-served basis on the day of performance. Call 212/861-PAPP. --