THE VOCABULARY of a U.S. Marine may include many adjectives, but "standoffish" and "bland" are not among them. Thus when the Oldest Post of the Corps forms up for its weekly evening drill and parade at its historic barracks in Southeast, it's one of the best free summer shows in town.

It's also one of the toughest tickets -- but if you try hard and succeed, you and your guests will be crisply rewarded.

The Evening Parade steps off at 2020 hours (8:20) every Friday through September 4 at the Marine Barracks, Eighth and I SE. If you're not there by 7:45, your spot in the bleachers will be given away.

At the barracks gates, the Marines check your name off clipboards, inspect purses and bags and relieve you of foodstuffs. Visitors pass through metal detectors, then are escorted to their seats by white-gloved Marines who pack nearly 5,000 people into bleachers running along one side and one end of the parade grounds. To get them all seated, they forgo aisles altogether, leading one young escort to discreetly inquire, before he penned the crowd in with newcomers, "Does anyone have to go to the bathroom?"

The drama of the two-hour show -- and it is a show, complete with music and spotlights -- is best seen from the side stands; end-zone seats afford a lesser view. Because of the attention the program demands -- silence for the National Anthem and "Taps," quiet for the Silent Drill Team, for example -- parents should consider babysitters for tots. You aren't allowed to walk around, even with a fussing baby.

The Marines' stage, a close-clipped parade ground surrounded by brick barracks, square brick residences and gateways on the street side, and the home of the commandant at the north end, sits on a site selected by President Jefferson. The quadrangle is used for offices, maintenance facilities and quarters for troops and officers, and has been home to the Marine Band since 1801.

Today, Marines stationed at the barracks provide security details for the president and various dignitaries, operate the Marine Corps correspondence school and the Marine Corps Institute, and march in both this parade and the weekly War Memorial Sunset Parade.

The regal three-story white brick house, dramatically lit from within during the parades, has been the residence of the commandant since 1806. Both it and the barracks site are national historic landmarks.

With these as backdrop, the Evening Parade is really a collection of events, beginning with a concert by the Marine Band ("The President's Own") under the direction of Col. John R. Bourgeois. The musicians, wearing red, white and gold uniforms, offer several selections, usually including a march by John Philip Sousa, who conducted the band around the turn of the century.

In the shadows of the barracks' covered arcades, wearing dark uniforms with white gloves and caps, the Marines have formed up. They come marching on immediately after the concert to music from the Drum and Bugle Corps, stand at attention for the Report and Officers' Call, then wait while Chesty VIII, latest in the line of Marine mascot bulldogs, gets his moment in the spotlight. Chesty trots on little burly legs across the parade grounds at the end of his leash, and, well, sits down momentarily -- perhaps it's his version of parade rest.

As the Marines march across the field, passing in review (two weeks ago to Sen. John Glenn of Ohio), the Drum and Bugle Corps provides a selection of marches. For Glenn, they played "Semper Fidelis," "Marines' Hymn," "Anchors Aweigh," "This Is My Country," "Colonel Bogey March," "It's a Grand Old Flag" and "Scotland the Brave." Visitors are expected to rise for the presentation of the colors -- Old Glory and the Corps flag, draped with campaign streamers -- and to be reasonably quiet. But inevitably the audience applauds, almost involuntarily at times, so impressive is the precision.

It all may be nearly routine for the troops, but the civilians are wowed. When the drill team, performing without verbal commands, tosses rifles with fixed bayonets from one to another, the audience seems almost afraid to applaud: What if they caused someone to lose his concentration?

"These guys really know what they're doing," someone whispers.

"They'd better," responds his companion, watching the bayonets flash in the field lights.

The Marines, all spit-and-polish and campaign ribbons, glittering brass bugles and gleaming rifles, close dramatically: A solitary bugler, spotlighted high atop the crenelated barracks building, sounds "Taps."

Good show.

A FEW GOOD PARADES -- To make reservations for parades through September 4, call 433-6060 from 8 to 11 a.m. and 1 to 3 p.m. Reservations open each Friday for the parade three weeks thereafter. You can also write to the Marine Barracks Adjutant, Eighth & I SE, Washington DC 20390. If you don't have reservations, queue up at the main gate for no-shows' seats, if any. Guests must pass through a metal detector, submit purses and bags to search, and surrender any foodstuffs.

Free parking is available at the Washington Navy Yard, three blocks away at 11th and N SE. Free shuttlebus service from the Navy Yard to the barracks begins at 6:30. By Metrorail, take the Blue Line to Eastern Market station, four blocks from the barracks.

Also by the Marines: The War Memorial Sunset Parade, Tuesdays at 7 through August 18 at the Iwo Jima memorial, featuring the Drum and Bugle Corps and the Silent Drill Platoon. Free parking at Arlington Cemetery National Visitor Center with free shuttle bus service; no reservations; seating on the lawn.