Heading to the final performance of this show at the Benedum, on Nov. 23, I wondered a little about accommodating myself to a revered novel about some of the country's most downtrodden people -- humans who breathed well within living memory -- rendered in an art form that's among the planet's priciest to produce. Simply on the level of formal expression, it seems problematic to take characters practically defined by the simplicity, even inarticulateness, of their speech, and make them communicate in powerful trained voices: They'd end start seeming powerful, which Steinbeck's Okies are anything but.

And yeah, hearing a baritone sing, "Them pigs they is all died off" is strange. But only at first. Composer Ricky Ian Gordon and librettist Michael Korrie's 2007 adaption (co-produced by the Pittsburgh Opera, although it premiered in Minneapolis) brilliantly and rather boldly retains the novel's spirit of populist outrage as well as its humanity.

The three-and-a-half hour show mostly follows the Joad family, from Dust Bowl despair to struggle, betrayal and a battered sort of redemption in California. But the show never stops reminding us -- with dark humor and biting wit -- about the economic and political machinery behind their misery.

In a barbershop-quartet style number, for instance, used-car salesman sing about stiffing hicks. But two longer set pieces really dig in. In the first, "Not My Fault," the buck for the bulldozing of the Okies' repossessed homes is passed from their hard-up neighbor who's just driven his tractor through the wallboards all the way to double-breasted bank regulators in Washington. In the second, the savage logic of capitalism is made simple as a California plum magnate (and his cannery workers) sing about pulling profits from the earth, crushing the little-guy competition -- and leaving the fruit to rot if the surplus would raise prices too much, even if hungry people are standing just on the other side of the orchard fence.

The show, with its vintage jalopy, catwalk, clever staging and video backdrop, was pretty grand spectacle, too. Its very slickness, in fact, felt like the Trojan Horse that let Gordon and Korrie (whom I interviewed for CP in October) smuggle their (and Steinbeck's) populist politics into the halls of elite entertainment, for an audience of people mostly sure, current events notwithstanding, that capitalism will never collapse on their heads like a dust-freighted clapboard shack.

But who knows what sinks in, and when? On my way out, I heard a young woman tell her older female companion (perhaps her mom) that the show hadn't been "uplifting" enough.

Then again, if a story about people stripped of what little they had helping other people with nothing doesn't move you, what could?