Some 63 years after it set the tone for Jazz Age musicals on Broadway, "Lady, Be Good!," the first of 14 shows George and Ira Gershwin wrote together, still has lots going for it. But I fear the revival of this landmark show, which opened Thursday night in the Kennedy Center's Eisenhower Theater, has just as much going against it.

The production has been put together by the Goodspeed Opera House, which specializes in the reconstruction of vintage musicals and prides itself on doing them as they once were done. That means reassembling lost books, restoring songs to their rightful place, retrieving original orchestrations and generally adhering to theatrical conventions that may have grown hoary with time.

The goal is commendable, but the results, in this case, are decidedly mixed. It's one thing to put "Lady, Be Good!" back together. You've still got to find performers who can animate its blithe idiocies, sing its gorgeous songs and deliver its sappy dialogue. With one or two exceptions, the Goodspeed cast is dreadful. Most of the leads are without charisma. The chorus is ungainly and unattractive. The comics are tiresome.

There has always been a flaw in the Goodspeed's ointment. Most of the musicals it wants so desperately to preserve were tailored for specific talents ("Lady, Be Good!" starred Fred and Adele Astaire, then America's favorite dance team) and traded heavily on their appeal. The Broadway musical was still struggling to integrate all its elements and in many ways functioned as a showcase.

That the books were inane was deemed unimportant, as long as they got the stars on and off with regularity. The songs didn't have to be particularly well motivated, if they were good songs and handsomely sung. Variety turns were dropped into the mix, usually because someone in the cast could do them well. What the Goodspeed can recreate is the original game plan. What it has great trouble duplicating -- or even approximating -- are the original players. Without equivalent talents, the enterprise invariably seems hollow and a little musty.

In addition to the title number, "Lady, Be Good!" has an abundance of musical riches -- "Fascinating Rhythm," "Little Jazz Bird," "The Half-of-It-Dearie Blues" and "The Man I Love," which was actually cut during the Philadelphia tryout, but has been reinserted into this production. Since the plot details the frivolous doings of the party-going set in a Rhode Island summer colony, there are more than enough occasions for dancing -- and not just the knock-kneed, elbow-flapping Charleston that was the rage, either.

For comic relief, you've got a drunk who's always seeing lizards in unlikely places, a double-talking lawyer with an eye for the girls, and a vengeful, pistol-packing Mexican, although the Mexican isn't that funny. Guy Bolton and Fred Thompson peppered their book with quips ("You remember me, surely." "Don't call me Shirley!") that had to be corny to begin with. The hitch is that nobody seems to know how to shuck corn these days.

When the show begins, Susie Trevor (Nikki Sahagen) and her brother Dick (Ray Benson) are being evicted from their house. Dick dearly loves Shirley (Kathy Morath). But without a penny to his name, it looks as if he's going to have to marry rich, autocratic Jo (Marlena Lustik), instead. Off the quibbling siblings go to Jo's fancy party, where Susie eventually falls into a scheme to earn some cash and stave off her unfortunate brother's marriage: She'll impersonate a Mexican senorita! (If you want to know why, all I can say is she has her reasons and in the long run they're a lot sounder than her impersonation.)

The rampant nonsense certainly looks pretty in the sets that Eduardo Sicangco has designed with a nod to the illustrations of John Held Jr. And Dan Siretta has cooked up some energetic dances that mesh like clockwork even as they suggest the abandon of an age that loved its bathtub gin. Director Thomas Gruenewald, at a loss as to how to put flesh on so many cartoon characters, at least tries to keep the pace from flagging.

By my reckoning, however, there is only one performance that looks easy and right in this madcap world of flappers and their beaus. It is given by Benson, a lantern-jawed leading man who has a bit of the young Dick Van Dyke about him. While all around him seem to be hurling themselves into the dances, he alone takes to the floor effortlessly, as if he were riding the crest of a breaking wave. His singing voice lacks distinction, but he makes up for it with sincerity and a pleasant disposition, and his enjoyment is contagious.

Sahagen makes a perky dance partner for him, drawing him into "I'd Rather Charleston" with childish mischief and then tagging along with unrepentant glee. But she's not much of a comedienne and her singing brings to mind curdled butter. Russell Leib, as the dithery lawyer, is saddled with a large share of the evening's jokes, about a third of which he makes work. That's not an altogether shameful percentage, although it still leaves the other two-thirds to fend for themselves.

Elsewhere, the performances drop off so drastically that it would verge on cruelty to point out individual shortcomings. Suffice it to say that neither youth nor beauty is being served, and that a show that should be sunny and spontaneous frequently looks all too grim and laborious.

The Goodspeed may have fixed up the property, but the new tenants are letting it go to seed. Lady, Be Good! Book by Guy Bolton and Fred Thompson. Music by George Gershwin. Lyrics by Ira Gershwin. Directed by Thomas Gruenewald. Musical direction, Lynn Crigler; choreography and musical staging, Dan Siretta. With Nikki Sahagen, Ray Benson, Steve Watkins, Iris Revson, Christopher Seppe, Marlena Lustik, Russell Leib, Kathy Morath. At the Eisenhower Theater through Nov. 28.