John Doyle’s signature stripped-down approach to musical theater — which earned him mid-career fame and a Tony via the 2005 “Sweeney Todd: The Demon Barber of Fleet Street” — has had its ups and downs. But the style is a good match for Brecht’s picaresque parable, “The Caucasian Chalk Circle.” While the director-designer’s penchant for having actors play instruments has sometimes seemed forced when levied on Broadway material conceived to be splashy, it meshes near-perfectly with this work’s modernist take on Brecht’s epic saga. And Domenique Lozano’s new A.C.T.-commissioned translation is vivid enough to merit a long life of its own, with or without Doyle’s imprint.

Written by Brecht in unhappy Hollywood exile during WWII, the play is set during wartime in an indeterminate past, as Grusinia (a Russian name for Georgia) fights Persia. When enemy forces invade the city of Nukha, the Governor is captured and his vain, self-absorbed wife (Rene Augesen) is so panicked she flees without taking their only child.

The babe is found by kitchenmaid Grusche (Omoze Idehenre), who has promised to spend the war waiting for the return of her betrothed, the soldier Simon (Nick Childress). She certainly doesn’t need to be harboring a blueblood child — one sought for execution by the conquerors — when safety, food and shelter are already at a premium. But abandoning this innocent is something her humanity can’t allow, even if that empathy is a quality few around her seem to share.

Without tumbling into a romantic sentimentality that might be anathema to Brecht, Doyle keeps the separated lovers’ yearnings alive by having Simon onstage much of the time, a silent witness in mind if not body to Grusche’s travails. (Other members of the ensemble remain in sight, seated on either side of the stage when they’re not actively needed.)

Those travails include dealings with war profiteers, upper-caste snobs, an edgy stay with a brother (Gregory Wallace) and his hostile spouse (Augesen), and a marriage of babe-legitimizing necessity to a mountain resident on his deathbed. He had only been playing sick to dodge the draft, however, suddenly “reviving” when the war is proclaimed over. It’s at this awkward juncture that Simon returns, appalled by his love’s “betrayal.”

Doyle and cast have reaped a bounty of satire, drama and even poignance from the tale to this point, using simple props and little real “set,” save a trash-littered open space bordered by chain-link fence and some hanging tarps. (Latter are deployed to striking effect as the rotting rope bridge Grusche and infant cross to escape capture.)

Nathaniel Stookey’s original actor-performed score for both conventional instruments and found objects is at once stark, playful and plaintive, with the thesps also performing slightly dissonant a cappella choral interludes. Not all are strong individual singers, but the lion’s share of solo vocalizing falls to the very capable Idehenre and Manoel Felciano (Tobias in Doyle’s “Sweeney Todd”) as the omniscient narrator.

The short second act disappoints a bit, because Brecht’s travesties of trial justice hit a more overtly vaudevillian tone that Doyle exaggerates, dissipating much of the prior emotional potency. He even lets the judge (Jack Willis, highly amusing — to a point) indulge in labored audience participation.

Still, the production is fresh and alert, qualities very much shared by Lozano’s first translation job.

Honoring the spirit rather than the letter of the original text, her expletive-riddled version shrugs off the stiffness of many Brecht translations, making Brecht’s barbed wit and social consciousness seem utterly contemporary — an effect underlined by a few up-to-the-moment political references.

Idehenre’s warmth and determination keep the show’s potential for overly intellectual/polemical impact at bay, while the otherwise multicast ensemble is first-rate.

The Caucasian Chalk Circle

A.C.T. Theater, San Francisco; 1,035 seats; $67 top

  • Production: An American Conservatory Theater presentation of a play in two acts by Bertolt Brecht, translated by Domenique Lozano. Directed and designed by John Doyle.
  • Crew: Lighting, Jane Cox; original music, Nathaniel Stookey; sound, Cliff Caruthers; dramaturg, Michael Paller. Opened, reviewed Feb. 24, 2010. Running time: 2 HOURS.
  • Cast: With: Rene Augesen, Nick Childress, Manoel Felciano, Anthony Fusco, Rod Gnapp, Carole Hewitt, Omoze Idehenre, Gregory Wallace, Jack Willis.
  • Music By: