Nicely-Nicely Johnson (Cameron J. Ross, right) leads the rousing Sit Down, You re Rockin the Boat, assisted by General Cartwrigh

With a show as perfect as Guys and Dolls — and universally acknowledged as such — the chief question one asks of each new staging is simply: does the production live up to the material?

Despite a bumpy start and misjudgments along the way, Theatre Under The Stars’ current mounting generally lives up to this classic based on Damon Runyon’s stories depicting a mythic Broadway of gutsy gamblers and brassy chorines — all perfectly captured in Frank Loesser’s inspired songs and Abe Burrows and Jo Swerling’s witty and deftly plotted book.

For a while at Thursday’s opening, it seemed the evening would be hit and miss. Things started promisingly as conductor Steven Jamail led a fine rendition of the Overture, capped by the appearance of a stage-filling lighted sign of the show’s title, a neat visual. But when the sign flew to reveal the opening Runyonland sequence of Times Square street life, Paula Sloan’s choreography proved pedestrian and the set backing it looked chintzy. The first song, Fugue for Tinhorns, was undermined when two singers’ mikes went out, turning the famous trio into a virtual solo.

So it went. Bushel and a Peck, Jen Cody’s first nightclub number as Adelaide, was hampered by ineffective choreography and odd costuming that made Cody look more like Dainty June in Gypsy. Yet, in the next scene, Cody scored spectacularly with her signature comic solo Adelaide’s Lament, a distinctive rendition ideal in characterization, timing and vocal delivery.

So there is a certain on-and-off quality to this Guys and Dolls. Though the leads are solid, the casting chemistry is short of perfection and takes several scenes to gel. The supporting team is uneven, not yet consistent in delivering the unique Runyonese patois. Director Roy Hamlin gives the overall rendition punch and pace, but there’s room for fine-tuning, picking up a few scene changes, and toning down some overly broad touches.

One other drawback is that Hamlin has decided to tinker. For instance, he inserts Nathan’s song Adelaide (an addition to the movie version) — a pleasant tune, but it doesn’t really fit where it’s placed here and it slows the Act 1 flow. Likewise, changing the title song from Benny and Nicely-Nicely’s duet into a chorus number for ALL the guys dissipates the song’s focus and energy.

Yet this rendition steadily improves through Act 1 as the two intertwined love stories take hold and the performances acquire definition. And its Act 2 is almost entirely on target, all scenes and numbers hitting their marks. Sloan’s choreography, largely indifferent in Act 1, takes off in the big Act 2 numbers, such as the insinuating Take Back Your Mink and the vibrant Crapshooters’ Dance.

Joseph Mahowald’s worldly, confident Sky and Susan Powell’s wary yet vulnerable Sarah have the strong legit voices to land such beautiful love songs as I’ll Know and I’ve Never Been I Love Before. Powell cuts loose engagingly in her buoyant If I Were a Bell, while Mahowald gives the right drive and urgency to Luck Be a Lady.

The diminutive Cody as Adelaide and the tall and lanky Matt Merchant as Nathan take some getting used to as a romantic team (he’s twice her height!) But her Adelaide is a comic gem and Merchant’s wry, offbeat take succeeds as a nervously jumpy Nathan, emitting little screams of panic. They develop a convincing, longtime couple rapport, especially in their Sue Me duet. And Hamlin’s staging at several points makes clever use of the disparity in their heights

Cameron J. Ross’ exuberant Nicely-Nicely and Kevin Cooney’s fatherly Arvide are stand-outs in the supporting cast – each with a standout musical moment, Ross leading the rousing revivalistic Sit Down, You’re Rocking the Boat, Cooney with the tender and poetic More I Cannot Wish You.

But as always, it’s the irresistible score and script that are this show’s real stars.

Guys and Dolls
7:30 p.m. Tuesdays-Thursdays, 8 p.m. Fridays, 2 and 8 p.m. Saturdays, 2 and 7:30 p.m. Sundays, through Oct. 9
Sarofim Hall, Hobby Center, 800 Bagby
Tickets: $24-$75; 713-558-8887