Has "Riverdance," the indefatigable international sensation, spoiled the rest of the world--or at least America--for more subdued traditional Irish culture? The question is provoked by Siamsa Tire, the National Folk Theatre of Ireland, which opened a two-week run Tuesday night at Ford's Theatre. The troupe's performance is long on cultural authenticity, but low-key and matter-of-fact to a fault.

"Riverdance" was inspired by Siamsa Tire's 1992 "Seville Suite," and the number is being reprised in Siamsa Tire's "Sean agus Nua '99 (The Best of the Old and the New)" at Ford's as three female flamenco dancers encounter three male Irish step dancers. In "Riverdance," that kind of culture clash results in a theatrical explosion of bravura technique. In Siamsa Tire's current edition, the meeting is tepid. And it's nearly the liveliest thing in the show.

Of course, the goal of Siamsa Tire (pronounced SHAME-sa TEER-a and translated as "merriment" and "homeland") isn't to impress the world with "Riverdance's" brand of flashy, ferocious dancing. Siamsa Tire's business is the preservation and promotion of Irish folk culture, and the production at Ford's amounts to a greatest-hits package, showcasing songs and danced myths that the company has created over its 30-year history. The performance is folksy and cheerful but often bogged down by a curatorial spirit. It plays like an artifact.

That's not to say there aren't some lovely moments in director John Sheehan's show. Sean Ahern lifts his light tenor voice in several numbers, most wonderfully in "Roisin Dubh," a patriotic song disguised (out of political necessity) as a love ballad. The chorus croons sweetly behind him as stars twinkle in the background.

A tribute to Irish step dancer Jack Lyons remembers an aged Lyons supporting himself on chairs as he taught his steps to the Siamsa Tire company in its formative years. Some dancers sit and some lean on chairs, creating a wonderful arrangement of feet gently swirling and tapping to a leisurely tempo. It's one of the most sheerly graceful Irish dances--a genre usually full of rigid hopping, angular tapping and swift kicks--that I've ever seen.

A similar tribute to dancer Jerry Munnix, the company's chief inspiration and Lyons's teacher, shows the young Jerry tracing the shapes of metal tools of his father's forge to create his own dance steps. This is terrific raw material, but instead of blossoming into a creative act, the number peters out in a plain explanation of fact: that Munnix's tradition has been handed down.

"This is what we do," the show says at such moments, "remember and preserve." It would be more theatrical to go a step further and actually make something fresh from such cultural legacies. That's the element that catapulted "Bring In da Noise, Bring In da Funk"--another show about celebrating cultural traditions--beyond mere archival display.

Much of the rest of the show is too simplistically conceived to be of interest. A generic battle between Celtic gods Lugh and Balor is rendered as a battle between good old good and evil, with characters dressed in black and white grappling undramatically. In an object lesson about saving the corncrake (an endangered bird), dancers dressed like cornstalks sway in the breeze--and yes, it's as corny as it sounds. Later, though, a quartet of step dancers stomps across the stage with a certain intimidating flair as a harvesting combine.

The troupe is composed of a core group of five full-time professional performers and supplemented by a volunteer "community company" of 15. But this uneven mix doesn't seem to be the root of the performance's naivete, nor is the problem that Siamsa Tire's humble show pales next to the high gloss and swagger of the better-known "Riverdance."

It's that the venerable material isn't performed with the passion, originality and sense of discovery that might make it come alive.

Siamsa Tire, The National Folk Theatre of Ireland. Directed by John Sheehan. Music director, Tom Hanafin; lights, Jimmy McDonnell. With Anne Herbert, Honor Hurley, Oliver Hurley, Jonathan Kelliher and Justin Walsh. At Ford's Theatre through Nov. 14. Call 703-218-6500 or 800-955-5566.

CAPTION: Siamsa Tire performs a program of Irish song, dance and myth at Ford's Theatre.