The West End Dinner Theatre in Alexandria is doing some things very well.

A former Kresge's in the Foxchase Shopping Center that has undergone a total transformation, it is easily the handsomest dinner theater in the area. Instead of subjecting its customers to the crush of the buffet table -- and an array of indistinguishable entrees in cafeteria steam plates -- it offers sit-down dinners in highly civilized style and spacious surroundings. If the fare at Saturday night's opening of the musical "On the Twentieth Century" is any indication, the West End Dinner Theatre could probably make it as a restaurant alone.

From the service to the decor, everything in front of the large stage is, indeed, shipshape. Which leaves "On the Twentieth Century."

I wish I could say it were better than it is. But this 1978 Broadway musical, with a tinkly operetta-ish score by Cy Coleman, and a tiresome book by those tireless recyclers of show business nostalgia, Adolph Green and Betty Comden, is a second-rate piece of camp. On Broadway, it was salvaged to a degree by some flashy star performances and some sensational scenic effects by Robin Wagner, calculated to dazzle anyone who ever dreamed over a Lionel locomotive.

But while the West End has marshaled a cast numbering more than two dozen (among them, a nucleus of Equity performers) and some sleek sets that are nice as far as they go, the fact remains that "On the Twentieth Century" never builds up a head of steam in this, its Washington premiere.

It is the story of a 16-hour train ride between Chicago and New York, during which a flamboyant -- and penniless -- showman, Oscar Jaffe (Ron Wisniski), attempts to revive his career by getting that famous platinum Hollywood star, Lily Garland (Robin Baxter), to sign on the dotted line for his next Broadway production. Lily was once Oscar's prote'ge' and lover, but movie success has gone to her head, and furthermore, her entourage now includes a preening gigolo, Bruce Granit (Jerry Christakos), who caters to her every whim.

Although the essence of "On the Twentieth Century" is 1930s madcap, its creators decided to treat the piston-driven shenanigans as mock opera. (Oscar, who will do anything to get his way, even resorts to one of those excessive last-act death-bed scenes.) But Coleman, usually the keeper of Broadway pizazz, contributed one of his least hummable scores for the occasion -- Offenbach, verging on off-putting. And Comden and Green's sense of parody, never all that acute to begin with, reached new lows with lyrics like: "She's a nut, she's a nut, she's a nut . . . But, but, but, but . . ." (give or take a few nuts and buts).

The latter lyrics are inspired by the antics of a certain religious fanatic and millionairess, Letitia Peabody Primrose (Maureen Kerrigan), who spends her time slapping "Repent" stickers all over the train and its passengers. The role was originally created by Imogene Coca, as is abundantly evident from the performance of Kerrigan, who doesn't seem to be playing Letitia Peabody Primrose as much as she is playing Imogene Coca.

Still, Kerrigan shows some spirit, as do the other principals. What is lacking is the overblown style that these self-absorbed creatures bring to the world, even when the world isn't looking. Wisniski and Baxter make the requisite grand gestures at the West End, but their performances are decidedly on the heavy side and further impede the musical on its mad race East. Among the supporting players, John Butz and Jesse Foreman do the most accomplished work, as Oscar's beleaguered flunkies; in the huff and puff of Jim Mumford's staging, I found myself searching them out repeatedly for the fun missing elsewhere.

For the time being, the good news at the West End is the plant itself and the management's apparent dedication to quality service. The real cheering will have to wait until "On the Twentieth Century" pulls out and a show that measures up to the facility pulls in. That, however, does not seem an unreasonable expectation.

ON THE TWENTIETH CENTURY. By Betty Comden and Adolph Green. Music by Cy Coleman. Directed by Jim Mumford; choreography, Todd Pearthree; set design, Tom Width; lighting, John Gray; musical direction, Kim Pensinger Witman. With Ron Wisniski, Robin Baxter, John Butz, Jesse Foreman, Jerry Christakos, Patrick Brian Collins, Maureeen Kerrigan. At the West End Dinner Theatre through Feb. 24.