The new musical at the Kennedy Center Opera House that purports to honor the life and artistry of Louis Armstrong is titled "Satchmo: America's Musical Legend." While this clears up any possible confusion among those who may have thought they were going to see "Satchmo: the Plumber," it also places an impossible burden on a show that can't begin to live up to its billing.

Armstrong was quite possibly the century's greatest jazz trumpeter and certainly one of its most distinctive showmen, every inch a pro. But this sorry musical, which opened last night for a run through Sept. 5, has amateur night written all over it. Not only does it trade ineptly on the memory of a giant, but producer Kenneth Feld has seen to it that you can purchase a boutique's worth of souvenirs in the lobby afterward.

Catch a rotten show and take a piece of it home with you. Who says enterprise is dead?

"Satchmo" has been written and directed by Jerry Bilik, who also contributed nearly a dozen songs of his own to accompany such Armstrong standards as "When the Saints Go Marchin' In," "Basin Street Blues," "St. Louis Blues" and "Mack the Knife." If, indeed, the standards were allowed to run their full course, we might be in a better frame of mind to put up with such Bilik drivel as "Red Beans and Rice," "Love, It's Not Easy" and "Callin' the Children Home."

But "Satchmo" doesn't work that way. The nominal star of the show is forever being elbowed aside for a garish production number, cut off just as his trumpet is warming up, relegated to the background by the overriding necessity to condense a decade into a few minutes of stage time. It's rather like attending a party where the guest of honor keeps getting shunted into the kitchen to make room for the crashers.

After a much-publicized search, the title role was conferred upon a 25-year-old unknown, Byron Stripling, who plays a mean trumpet, but whose impersonation of Armstrong is rudimentary at best. As Armstrong ages -- the show covers nearly 60 of his 71 years -- Stripling applies white shoe polish to his hair.

He is such an earnest performer that you hate to take him to task. But he has few acting skills and little natural charisma, and he is so obviously overwhelmed by the show he is supposed to carry as to inspire deep feelings of commiseration. This is not exactly Armstrong's joyful legacy.

The show itself could probably serve as a textbook example of how not to write a musical. What little story "Satchmo" has to tell it tells poorly. Armstrong's life -- although it began in poverty and included a stint in a home for wayward waifs -- is not one of resounding conflict. He married four times, but the tumult that may have existed on that front is quickly dispensed with.

The celebrated cornetist Joe (King) Oliver (James Rowan) served for a while as his mentor and surrogate father, until Armstrong, at the urging of his second wife Lilian (Matilda A. Haywood), broke away for stardom. If that caused a stir in Armstrong's generous heart, "Satchmo" glosses over it. In fact, as Bilik has written the scene, Armstrong is offstage when Lilian takes it upon herself to inform Oliver of the rupture. For his part, Armstrong, presented with a fait accompli, is allowed a hangdog look.

The truth is fame came early to Armstrong and continued, largely unabated, until his death. "My life has been my music," he once said. "But the music ain't nothin' if you can't lay it on the public. The main thing is to live for that audience." No doubt, that is what made him a favorite the world over, but it is also what makes "Satchmo" so dramatically flaccid.

Bilik attempts in one clumsy episode, set in a Memphis jail, to paint Armstrong as a crusader for civil rights. A second scene, transpiring in Ghana, has the entertainer proudly asserting his African heritage. As depicted here, both moments are hard to buy. They're more in the nature of high-minded pronouncements, shoehorned into a flossy entertainment to give it depth and resonance.

The real essence of Armstrong was his ebullience, his ability to catch up thousands with a smile as wide as a piano keyboard and a voice once described as "sandpaper calling out for its mate." All the musical really finds to do is to chart the growth of his fame by jumping from one gig to the next. What happens in between is conveniently summarized by secondary characters, who are apt to say things like, "He doesn't know it, but he's changed the sound of music across this whole damned planet."

The various engagements serve as the occasion for a series of production numbers, staged by Maurice Hines, who gets the chorus doing a fancy cakewalk in New Orleans and a kinetic tribal dance in Ghana. Even the prisoners in the Memphis jail, where Armstrong is momentarily detained, are given a syncopated routine that seems unduly beholden to the chain gang sequence in Bob Fosse's "Big Deal." This is just so much frosting on the cake, except there's no cake.

Actors who play instruments being a rare breed, "Satchmo" has been cast primarily with musicians, who generate some excitement as long as they don't have to talk. A gifted director might be able to coax believable performances from this crew, but Bilik lets them fumble for an emotion and then, when an emotion is miraculously located, overstate it wildly.

If "Satchmo" is to have any future on the road (Broadway would be instant death), the first order of business is to bring in a chevroned director who can impose some shape on this sprawl. Massive rewrites couldn't do any harm.

Producer Feld comes from the world of the circus, where bright costumes, blaring music and the old hustle-bustle are part of a time-honored mix. Strange how cheap and exploitative it all looks in a theater. This musical even has a ringmaster of sorts, who prods the audience into shouting "Satchmo" back at him, because "just sayin' it makes your whole face feel good."

So quickly does "Satchmo" exhaust the good will its fabled subject tirelessly built up over the decades that by the end you may want to holler out something else. "Gimme my money back" springs to mind.

Satchmo: America's Musical Legend, written and directed by Jerry Bilik. Choreography and musical staging by Maurice Hines. Original music and lyrics by Bilik; musical arrangement by William Pruyn. Sets, Edward Burbridge; costumes, Judy Dearing; lighting, Thomas R. Skelton. With Byron Stripling, Ebony Jo-Ann, James Rowan, Matilda A. Haywood, Elliott Goldwag, Doug Barden. At the Kennedy Center Opera House through Sept. 5.