In Act II of “Porgy and Bess’’ a fierce storm bears down on the characters of Catfish Row, and Gershwin conjures it with a swirling orchestral tempest, complete with the ringing of a hurricane bell.

Surely the question ran through the minds of most present here for Friday’s concert performance of the opera: How soon and how fully would life imitate art? Irene began drenching Western Massachusetts some 24 hours later, with the BSO calling off its season-closing performance of Beethoven’s Ninth Symphony, the first such cancellation in 75 years.

Saturday night’s all-Beethoven program with Itzhak Perlman took place as scheduled. At least there was an enjoyable “Porgy.’’

The opera has been much in the news of late thanks to the production set to open at the American Repertory Theater, en route to Broadway, which has already generated controversy based on early press reports of director Diane Paulus’s plans to adapt the original opera with an eye toward modernizing the piece, filling out the backgrounds of various characters, and even fashioning a happier ending for the work.

While the ART’s production officially opens its doors to reviewers tomorrow, Friday night’s vibrant performance of the original score, albeit with some over-aggressive cuts, left one with the impression that Gershwin’s masterpiece has hardly been languishing as it awaits the revisionism of Paulus and her team.

The multivalent brilliance of Gershwin’s score, deftly shaded in a good performance, fills in so many of the apparent holes that may be spotted when the libretto is read on paper. Friday’s rendition in fact brimmed with a theatrical vitality that carried it far from the typical concert opera presentation of singers planted on stage holding scores.

The cast sang from memory and was set free to roam at the front of the orchestra in what amounted to a light staging. At its heart was the British conductor Bramwell Tovey, in his BSO debut, conducting with a sure hand and a clear affection for this score’s roiling amalgam of classical, jazz, and vernacular traditions, invented or otherwise.

Tovey didn’t so much thread the needle between styles as he did make the score’s disparate musical inheritances feel like they belonged together, which is not always the case with “Porgy,’’ a work often hailed as a masterpiece yet still fated to wander between the worlds of opera and musical theater.

At times the BSO itself seemed to be the least persuaded party on stage, turning in a respectful and accurate reading that sometimes edged toward the blandly polished. The members of the Tanglewood Festival Chorus, meanwhile, threw themselves wholeheartedly into their roles, as if Tovey had encouraged them to not only sing but to participate as full partners in the drama unfolding on stage. They remained on the risers behind the orchestra but broke their typically uniform ranks to respond as a mass of individuals swept up in the events before them. And if acting at times slid toward overacting, the chorus’s sheer commitment lent the affair a kinetic energy that drove the night’s momentum and supported the contributions of the strong cast.

Laquita Mitchell showed off a supple and refined soprano as Bess, infusing the role with a touching vulnerability and innocence yet at the same time an awareness of her own weakness that gave her portrayal a weightier pull. When in Act I, the drug dealer Sportin’ Life tries to play on her fears and lure her off with him to New York, Bess replies, “I ain’t come to that yet,’’ with the key word of course being the last one, which Mitchell sang with a heartbreaking sense of knowing.

Alfred Walker was a regal and sympathetic Porgy, singing with a smooth and shapely bass-baritone and a shadow of melancholy that not even the resolutely cheerful “I got plenty o’ nuttin’ ’’ could fully displace. Nicole Cabell as Clara, Marquita Lister as Serena, and Gwendolyn Brown as Maria all gave fine performances, as did Gregg Baker as a formidable Crown, John Fulton as Robbins, Robert Honeysucker as the lawyer Frazier, and Jermaine Smith as a sleekly conniving Sportin’ Life.

It came as some surprise that, in the BSO program, the work was listed as “The Gershwins’ Porgy and Bess,’’ the same title that has itself become a flashpoint for some of the controversy around the new ART production. It turns out that this title was in fact mandated by the Gershwin Estate, according to the BSO, as “a condition of using the required rental performance materials.’’

It’s not, in short, part of Paulus’s reinvention, which in a way makes it more insidious. We may often refer to operas in shorthand as the creation of their composers (Mozart’s “Don Giovanni,’’ Strauss’s “Rosenkavalier’’) but for the Gershwin Estate to stipulate this title as the required billing is to grossly undervalue the contributions of DuBose Heyward. As Stephen Sondheim pointed out in his colorfully furious letter to the New York Times, Heyward was the author or coauthor of the opera’s most memorable lyrics. He was also the author of the original novel, “Porgy,’’ without which there would be no “Porgy and Bess.’’