"Let's remember that Gershwin marked this as forte at the top," John Mauceri is saying, his head just visible above the wall that separates the orchestra pit from the front row of seats. He has just interrupted "It Ain't Necessarily So," the drug dealer Sportin' Life's sparkling number in Porgy and Bess, to correct the chorus's timing on "Wah-do!"—which, to be fair, isn't a line that comes up much in the standard opera repertoire. Mr. Mauceri holds up his baton. "Here we go. One-two-three-four—" Then the chorus is back in full voice and the orchestra is playing a score as original, as colorful, as brilliant as any in opera.
This year Porgy and Bess turns 75, having had its premiere on Broadway in 1935 (it closed after 124 performances and mixed reviews). Mr. Mauceri—a former director of the Hollywood Bowl Orchestra, former music director of the Pittsburgh Opera, and former Yale University professor, among other titles—is taking time off from his day job as chancellor of the University of North Carolina School of the Arts to conduct the work for the Washington National Opera, of which he is also a former music director. The run opens on Saturday in the Kennedy Center's Opera House.
Mr. Mauceri has a particular fondness for Porgy and Bess, George Gershwin's only opera (the composer died two years later, at age 38). "Every aspect of this opera exposes and celebrates the American experience," says Mr. Mauceri, who notes that Gershwin was born Jacob Gershowitz, the son of Jewish parents who had left Russia for Brooklyn. As a teenager, he went to work for a Tin Pan Alley music-publishing company, and his first big hit was "Swanee," a song popularized by Al Jolson in 1920.
By the time Gershwin began Porgy and Bess, says Mr. Mauceri, he had already written popular songs like "Fascinating Rhythm" and "Lady Be Good"—frequently with his brother Ira as lyricist—as well as Rhapsody in Blue. Even so, many in the opera world took it as an affront that a Jewish songwriter with Tin Pan Alley roots would attempt an opera, to say nothing of one with an almost-all-black cast. But the cast puts Porgy and Bess in important company, Mr. Mauceri says: Along with shows like Showboat and West Side Story, it helped set the stage for civil-rights advances by giving middle-class white audiences sympathetic introductions to people and situations they might never have encountered otherwise.
After Gershwin's death, a producer created a successful 1941 production that matched songs from the opera with lines from the earlier play on which the opera is based—Porgy, by DuBose and Dorothy Heyward—to make a conventional musical. It was not until the 1970s that a fully operatic version of the work was created from the original score, but it was so long that most productions made drastic cuts.
Musicologists, among them Mr. Mauceri, eventually concluded that George Gershwin himself had made numerous cuts for the 1935 production that were never marked in the score but could be reconstructed by looking at the 1935 orchestral parts, which Mr. Mauceri studied in Yale's Beinecke Library. In 2006 he and the Nashville Symphony Orchestra recorded a version of the opera that had played on Broadway in 1935.
What Washington audiences are hearing during the current run is a 2005 production directed by Francesca Zambello. But as conductor, Mr. Mauceri is bringing some of what he learned in recreating the 1935 version, including Gershwin's tempo markings. In any case, he says, "the work is so strong that it triumphs in all its various forms."
Indeed, in rehearsal it sounds fantastic—"Summertime," "My Man's Gone Now," "I Got Plenty o' Nuthin'." Mr. Mauceri—now leaning forward on the podium, now swaying, now rising up on his toes—glances at the cellos, nods to the chorus, brings in one or another of the principals. Then the duet "Bess, You Is My Woman" begins, and there in the vast empty opera house it seems as beautiful an interplay of voices and strings and rhythm and emotion and history as any republic could hope to deserve.