What if what’s wrong for everyone else is right for you and your family?

That’s the dilemma that faces the Undershaft family in Major Barbara, Theatre Calgary’s stellar co-production (along with San Francisco’s American Conservatory Theatre) of George Bernard Shaw’s engaging — but undeniably talky — drama that opened Friday at the Max Bell Theatre.

Even more challenging for the family is the fact that not only is their fabulously wealthy — and wholly emotionally absent — father Andrew (Dean Paul Gibson) a weapons manufacturer who got rich dealing in death and destruction, but he’s also kind of a charmer.

That’s who Stephen (Stafford Perry), Sarah (Elyse Price) and particularly Barbara (Gretchen Hall) must try to resist when their aristocratic (and broke) mother Britomart (Kandis Chappell) announces one night that Andrew is dropping by for the first time in a couple of decades to straighten out the family’s less-than-optimal economy of scale.

Britomart might come from the right side of the tracks, but all she really brings to the table is her imperious manner and a fierce determination that her children be taken care of by Andrew, despite the fact that she feels he earns his living immorally.

On the other side of the ledger sheet, Dad Andrew might have money and power and social respectability, but that doesn’t change the fact that there’s two things missing from his rags-to-riches story: any sort of heir to the Undershaft empire, and any sort of relationship with his children.

There’s the son, Stephen, but he is so inconsequential that Andrew doesn’t even recognize him, let alone make him the heir apparent.

The real connecting thread is with daughter Barbara, a righteous fire pistol who disapproves of everything Andrew stands for.

She has rejected her wealthy family’s lifestyle to save souls as a major in the Salvation Army, where she lives on a pound a week, and has fallen in love with Adolfus (Nicholas Pelczar), an impoverished Greek professor from Australia who’s so nuts about her, he pretends to care about saving souls and joins the Army.

It’s all talk, all ideas — think theatre — delivered in gusty blasts of Shavian oratory that wheezes from time to time, but in fact feels relevant to these times and our lives.

It doesn’t hurt that this cast, a hybrid of Calgary-based actors (and Gibson, a Theatre Calgary regular who divides his time between Vancouver and London) and various members of the American Conservatory Theater based out of San Francisco, find the melody in Shaw’s sentences more often than not.

Hall has a tricky task, trying to communicate what makes Barbara tick without coming across as overly pious or self-righteous, and she locates just the right combination of moral clarity and genuine emotion to make Barbara feel real.

Cannell, as the aristocratic Lady Britomart, is wonderful — she is the only straight line in a family full of wavy ones, and she long ago made peace with that realization and tries to work around it, often to terrific comic results.