In the dim light of an old Charleston courtyard, Clara sings her baby to sleep with “Summertime,” as fragrant and soothing a lullaby as exists in American music. In the distance, the humming of the women’s chorus evokes the humid mists of the night.

In the Atlanta Opera’s appealing production of George Gershwin’s “Porgy and Bess,” conductor Keith Lockhart (of Boston Pops fame) often had the orchestra and chorus sounding like they were playing Debussy -- a rich, impressionistic palette of sound that cradled soprano NaGuanda Nobles for the first of the opera’s many hits.

The artistic and box-office successes of “Porgy” at the Cobb Energy Performing Arts Center -- all four performances were sold out -- is the latest piece of well-planned good luck for the often-beleaguered company.

It’s the second time the company has staged Gershwin’s brilliantly imperfect opera, which collects the many strains of American music on one stage, with sounds of spirituals and gospel, jazz, blues, Yiddish folk and classical opera traditions seamlessly blended. Yet the libretto includes too many characters and never quite settles on how seriously to draw the main roles. What’s the focus of the story? The doomed love triangle or the remarkable residents of Catfish Row? And where the optimism at the end speaks to the American can-do spirit, you leave the theater feeling it’s an emotional cop-out.

Suffice it to say the Great American Opera has its complications. Among them is fielding a large and virtuosic chorus, which the Gershwin estate dictates must be entirely African-American.

When the Atlanta Opera first performed “Porgy,” in 2005, chorusmaster Walter Huff had assembled a chorus that drew international raves: It was invited by Paris’ Opéra-Comique to perform in France, Spain and Luxembourg.

Huff’s chorus is again the star of “Porgy,” and I have never heard more impassioned and precise versions of “Overflow” and “Leavin’ for the Promised Land.”

Most of the cast was making an Atlanta Opera debut. Baritone Eric Greene was a ferociously charismatic Crown, the wild and vicious drug addict whose crime and punishment drives the opera’s plot.

Atlanta native Michael Redding, a bass-baritone with a clear voice and generous delivery, sang Porgy two-dimensionally, as a strong personality without much vulnerability. Vocally, Laquita Mitchell’s Bess was true to character: She is past her youth, she snorts “happy dust” and lives in the fast and dirty lane. To that end, the bloom is off Mitchell’s soprano, although her singing was always assured.

The opera’s many small roles were generally well cast, with Aundi Marie Moore’s Serena a standout, along with Chauncey Parker’s show-stealing Sportin’ Life and Justin Lee Miller’s Jake.

Directed by Larry Marshall, the production originated at the University of Kentucky, with high-definition video scenery developed by its Center for Visualization and Virtual Environments. Virtual sets have been used in Europe for a few years. Some of the “Porgy” images, collected by Richard Kagey, were strikingly effective, such as the hurricane scene of punishing waves and palm trees ready to snap in half.

But there was a flaw in the sociological concept. “Porgy” premiered in 1935, and like most great operas, can be reimagined in many settings. But this production team erased notions of an impoverished underclass, the essential element that motivates all the characters.

The scrubbed-clean houses (which now belong to Charleston’s super rich) and elegant vintage costumes (designed by Judy Dearing) were simply too proper and too middle class for a community with such low self-esteem, one that tolerates open-air drug dealing, gambling and murder and can’t raise a few dollars for a funeral. In neutralizing the daily horrors of Catfish Row, the production pruned back some of the explosive joy, too.

Pierre Ruhe is classical music critic of www.ArtsCriticATL.com

Opera Review

"Porgy and Bess"
Atlanta Opera. 8 p.m. March 4 and 3 p.m. March 6. Cobb Energy Performing Arts Center, 2800 Cobb Galleria Parkway, 404-881-8885, www.atlantaopera.org.