“The Times They Are A-Changin’,” director-choreographer Twyla Tharp’s garbled stab at converting Bob Dylan’s song catalog into a sinister Felliniesque carnival, may fail as dance theater or as musical theater or even as basic entertainment. But at least it fails big.

Ms. Tharp is aiming for something challenging and profound, a visual analogue to Mr. Dylan’s irascible roots-rock myths. And just as Mr. Dylan’s weakest albums still eclipse so many of their contemporaries, I’d personally rather watch Ms. Tharp flounder than see so many other directors succeed at lesser tasks.

As rock ‘n’ roll’s resident sphinx for more than 40 years, Mr. Dylan would appear to be resistant to the “jukebox musical” format, one of the more suspect trends to reach Broadway in recent years. Since shedding his earnest-folkie persona in the late 1960s, the cryptic Mr. Dylan has worn many hats and retained a crucial sense of mystery about his musical and lyrical choices, all of which could easily get in the way of creating a viable theatrical framework.

Ms. Tharp, a modern-dance icon whose “Movin’ Out” marked a high point among jukebox musicals in 2002, has jettisoned any sort of naturalism and instead set more than two dozen Dylan songs within a ragtag, underpopulated circus. The wall-to-wall dancing that punctuated “Movin’ Out” has given way to an array of big-top antics that wouldn’t be out of place in a “Cirque du Soleil” ode to Americana, with the three lead performers singing at some remove from the intrepid seven-member ensemble. The result is occasionally galvanizing and usually misguided, but almost never boring.

For all its athletic virtuosity, “Movin’ Out” was a bit muddled in its use of Billy Joel’s music to advance the narrative of Vietnam-era disillusionment; the storytelling frequently shifted from lyric-specific exposition to pure abstraction without sufficient guidance. “Times” dispenses with this concern altogether. In lieu of any sort of comprehensible plot is a ludicrously thin amalgam of Freud and “La Strada,” with the abusive ringmaster Captain Ahrab (Thom Sesma) and his rebellious son, Coyote (Michael Arden), vying for the affections of a morose brunette named Cleo (Lisa Brescia).

Certain tunes fit this setting quite well — “Maggie’s Farm” is a surprisingly apt hymn to the circus clowns’ newfound freedom — while others feel incredibly awkward. The fact that any other setting would probably be equally unsuitable to the Dylan canon will likely do little to mollify his notoriously zealous fans. Nor will John “J.J.” Jackson’s deft harmonica work in the pit orchestra (Michael Dansicker and Mr. Dylan contributed the rock-solid orchestrations) or the “Subterranean Homesick Blues” in-joke during “Like a Rolling Stone” set them at ease.

Judging from Ms. Tharp’s song selection, the times haven’t a-changed that much since 1967. All but three of the songs in the intermission-less show’s first half were written before Mr. Dylan’s 28th birthday, and the ratio improves only slightly from there. (A curious exception is a glut of material from 1979’s “Slow Train Coming,” the first album he recorded after becoming a born-again Christian.) The three albums that have marked yet another comeback for Mr. Dylan over the last decade are represented by only two songs.

But even with the preponderance of material from Mr. Dylan’s early, folk-heavy phase, Ms. Tharp steers clear of his political content. The show may open with Mr. Arden’s plaintive rendition of the title song, but don’t bother listening for the verse about a “battle outside” threatening senators and congressmen — it’s not there. And while “Masters of War” does get prominent placement, it receives some of the show’s weakest choreography, a wiggly mass of smoke machines and midriff-exposing beefcake.

Instead, Ms. Tharp has run off and joined the circus, with sporadically dazzling results. The trampoline work and rope tricks are particularly inventive, and she makes good use of both Jonathan Nosan’s contortionist skills and “Movin’ Out” veteran John Selya’s effortless virility. She also spurs lighting designer Donald Holder into one magnificent visual after another as he trains spotlights, footlights, and even flashlights all over Santo Loquasto’s resourceful set.

And now and then, “The Times They Are A-Changin'” attains a dream-like blend of illogic and inevitability. “Don’t Think Twice, It’s All Right” works surprisingly well as a Broadway power ballad, even with Jason McDole’s frantic performance as Cleo’s dog upstaging the talented Ms. Brescia. Even less obvious is the oddly resonant juxtaposition of Mr. Arden gently crooning “Mr. Tambourine Man” from atop an airborne moon while the rubber-limbed Charlie Neshyba-Hodges supplies a supple dance on the ground.

More often than not, though, the yoking of music to narrative feels perfunctory. The stilts and tightropes and trampolines carry with them a whiff of bells-and-whistles hucksterism, an admission that the underlying material just won’t hold audience interest on its own merits. This concern is borne out whenever the props get put away, as in a pointlessly rowdy “Please, Mrs. Henry.” The would-be showstopper, a high-energy free-for-all set to “Like a Rolling Stone,” feels so disengaged from Mr. Dylan’s inscrutable imagism that the only possible response is to tap one’s toes and pretend the song is completely unrelated to Mr. Dylan’s original tune. Ms. Tharp’s stage chops make this option more tempting than you might think, but not tempting enough.

“Nobody Sings Dylan Like Dylan,” admonished a print ad by his record label in the 1960s. The campaign may have been part of a misguided effort to steer folkies away from cover versions by the nefarious likes of Peter, Paul & Mary and the Byrds, but the message remains indisputable. Ms. Tharp wisely steers her singers clear of any attempt at approximating Mr. Dylan’s inimitable croak, but the addition of Broadway pizzazz to Mr. Dylan’s earthy melodies is not always welcome.

The lion’s share of the vocal pyrotechnics fall to the boyish Mr. Arden and his yearning, effective tenor.(He also proves to be a surprisingly dab hand during his brief dance sequences). Ms. Brescia is particularly proficient with the country-inflected tunes, and Mr. Sesma offers an uncompromisingly dark take on the cartoonishly evil Ahrab. But all three find themselves grappling with lyrics that ill serve their characters, and all three fall short on at least one occasion. The seven members of Ms. Tharp’s ensemble are clearly dancers first and singers second, but they handle their occasional vocal responsibilities well enough.

It remains to be seen what the Dylan faithful — who worked themselves into a lather over an electric guitar at the 1965 Newport Folk Festival, for crying out loud — will make of this undernourished mishmash. From a theater-goer’s perspective, messes like “The Times They Are A-Changin'” don’t come around very often. Perhaps they don’t come around often enough. Or perhaps they do.

Open run (256 W. 47th St., between Broadway and Eighth Avenue, 212-307-4100).