It must have seemed like a winning idea — casting a portly man in drag with little evident vocal training as Mary Poppins' rival nanny, Miss Andrew. To underscore the polarity, he's black, and costumed like a funeral float, in contrast with the title character's alabaster skin, cherry-red lipstick and colorful garb.

The problem is, this pairing unwittingly triggers throwback tropes of black mammies and white Scarletts, making this "Mary Poppins" an object lesson in the tricky business of so-called colorblind casting.

It's a boo-boo that mars director/designer Joel Sass' ambitious production at Artistry in Bloomington, which boasts gorgeous lead performances, energetic dances by choreographer Joe Chvala and beautiful music under the baton of Anita Ruth.

"Poppins" is a show about, among other things, the conflict between nature and nurture in 1910 England.

The well-to-do Banks family — aloof father George (Charlie Clark), ex-actor mom Winifred (Andrea Wollenberg) and terrible tykes Jane and Michael (Kate Regan and Josh Bagley, who alternate with Mabel Weismann and Liam Beck O'Sullivan) — is at a crossroads. These foot-stomping, tantrum-throwing kids have run off their latest caretaker even as their father, a banker, may lose his job.

Enter Mary Poppins (Becca Hart), the can't-lose nanny who sometimes floats away holding an umbrella and navigates class distinctions just as easily. With her chimney-sweep friend Bert (C. Ryan Shipley), she can solve the Bankses' problems with a spoonful of sugar and bits of magic.

A major challenge for any "Poppins" director is to honor a beloved property while bringing new touches to it. The 1964 Disney film, which starred Julie Andrews and Dick Van Dyke, is a sugary landmark. Playwright Julian Fellowes, later of "Downton Abbey" fame, wrote this stage adaptation, which bowed in England in 2004 and on Broadway two years later, touring to the Orpheum Theatre in 2009. Choreographed and codirected by Matthew Bourne, it featured Bert tap-dancing up a wall and on a ceiling and Mary flying in.

Michael Brindisi staged "Poppins" at Chanhassen Dinner Theatres in 2015, accenting other parts of the story to compensate for the fact that Mary doesn't fly. The "practically perfect" nanny doesn't fly in Artistry's version, either, a huge production that had a few hitches on opening night.

Still, this "Poppins" has performances worthy of celebration. Hart's Mary is a self-assured being of power and beneficence. The actor, who was part of the standout ensemble of "The Wolves" at the Jungle, never strains to assert her authority. Her charisma, voice and authenticity go a long way toward redeeming the production.

She is well matched with Shipley, whose Bert is a font of winning wholesomeness. A true triple threat — singing, dancing and acting with aplomb — he and Hart lead the company on the show's well-earned showstopper, "Step in Time," a big, complicated tap number.

"Supercalifragilisticexpialidocious" also is a highlight.

But back to casting: It's not a comment on the talent of Brandon A. Jackson, whose Miss Andrew and a queen are tonally out of sync with the production, that it doesn't work here. An eager beaver, Jackson has thrown himself into various performances around town, some of them commendable.

"Poppins" opened just as "Hamilton" was ending its six-week stay at the Orpheum. Lin-Manuel Miranda's blockbuster shows how colorblind casting should be done, pairing talented actors of every stripe in all kinds of roles but doing so in a manner that enlarges the story — and the audience's consciousness, as well.

rpreston@startribune.com • 612-673-4390 • Twitter: @rohanpreston