The stage of the Robert Baustian (formerly Black Box) Theatre is transformed into Lawrence in 1950, and as Ferrando exclaims “goldarn it” in the opening “La mia Dorabella,” our town feels a long way from Vienna in 1789. But the feeling soon passes, as this production’s splendid voices and Mozart’s incomparable music enchant the audience into a willing acceptance that this story could have happened here or anywhere — so long as it sounds this good.

Tim Ocel as stage director and Mark Ferrell as music director and pianist have put together a wonderfully integrated production in which the power of ensemble is felt in both acting and singing.

The opera, sung in English, tells of two sisters and the test of their fidelity proposed by the older Don Alfonso to their soldier fiances. The cynical Alfonso bets the two men a thousand dollars that if they leave, ostensibly going to war, their sweethearts will shortly be unfaithful to them. They take the bet, depart for battle, and then quickly return in disguise, with each courting the other’s lady love. Alas for constancy, the men prove irresistible, losing the bet and presumably their peace of mind as they struggle to come to terms with the saying of the opera’s title, roughly: “They’re all like this.”

The rich soprano of Gina Galati as Fiordiligi handles the part’s coloratura arias convincingly. She portrays her character’s conflicted feelings creditably, resisting her new suitor longer than her sister manages to do, but ultimately yielding. The blend of her voice with that of Holly Wrensch as Dorabella, her sister, is perfect and provides some of the evening’s most beautiful moments.

Wrensch offers a lovely floating soprano combined with a ton of acting talent. She plays a killer comic scene as she sings a beautiful, despairing song (“Smanie implacabili”) at the men’s departure, while changing into pajamas, bathrobe and sleep mask. Her animation later as she sings to Fiordiligi in praise of giving in (Mozart’s “Ã amore un ladroncello”) is also a treat to watch.

Baritone David Lara plays Guglielmo, Fiordiligi’s fiance, with macho assurance, while Brandon Snook as Dorabella’s sweetheart Ferrando brings a fine tenor to the part. Like the distaff principals, the two men blend well in their duets. Moreover, throughout the performance, the numbers sung together by these four and the other two principals demonstrate how ensemble singing should be done.

Tyler Simpson as the worldly Don Alfonso plays his part with a nicely ironic touch as he proposes his bet against the ladies’ constancy and offers cynical advice to the young lovers. Julie Maykowski, the sisters’ domestic servant, won over the opening-night audience with her comic ability, appearing disguised as a bearded doctor (who revives the “poisoned” lovers with jumper cables!) and as a brown-suited and mustachioed notary who prepares the marriage contract. Her soprano voice does credit to the role as well.

Erhard Rom’s set economically conveys mid-century Kansas; Marcus Doshi’s lighting is exceptionally effective, especially his dramatic use of footlights; and Mary Traylor’s costumes, including the men’s sensational biker outfits, keep the audience involved.

The show continues at 7:30 p.m. today, Tuesday-Wednesday, Friday-Saturday and Feb. 7.