With a cast of more than two dozen, a massive, gorgeously evocative set, and even a live lamb, Chicago Shakespeare has spared little expense with its much-anticipated revival of Gypsy (directed by Chicago Shakespeare’s associate artistic director Gary Griffin). But some less-than-fully-realized performances make this production about the quintessential stage mother—really the story of an indomitable woman's determination to realize her dreams even in the face of relentless disappointments—alternately thrilling and frustrating.

First, the good: Griffin wisely roots Gypsy in the grit and desperation of the Great Depression. A huge, filigreed frame that looks like the fading remains of a once-grand vaudeville palace dominates Kevin Depinet’s set. Rose's home is a drab, grimy-looking box. And when we first meet Rose and her daughters, there's something hauntingly hardscrabble about them. Gawky shy Louise and precociously cheerful Dainty June may be hard-selling chirpy song and dance numbers, but you can sense the sweat and the urgency under the selling. With their various newsboys/farmhands/patriot soldier retinue of backup chorus boys, they're living in fleabags, subsisting on day-old eggrolls.

The inherent contrast between the glittery luxe of showbiz stardom that Rose obsessively insists is just around the corner and the grim, exhausting reality of endless road-trip from one tawdry theater to the next is always apparent, even when Dainty June is at her cutesiest. The girls, of course, are crucial to the success of Gypsy. As the pre-adolescent June, Emily Leahy squeaks and struts like a cut-rate Shirley Temple. Caroline Heffernan's Young Louise is heart-tugging as the sister always stuck wearing the cow costume. Or so she is until Rose pushes grownup Louise (Jessica Rush) onstage as a stripper. It's there that the ugly duckling morphs into a swan, and Louise becomes Miss Gypsy Rose Lee.

Rush transitions from Louise into Gypsy in the space of a single song in an evolution that's vivid and palpable. She doesn't literally light up like her stripper colleague Electra, but you can practically see the glow come over her from the depths of her eyes outward. But after that transformative moment, Rush looses the spark. In the quick-costume change strip sequence, she's capable but not incandescent; you don't see in her the charismatic superstar that the role demands.

Similarly, Louise Pitre’s Mama Rose doesn’t really let loose until the show-stopping "Rose's Turn." That final number is at once a nervous breakdown set to music, a galvanic redemption, and a cathartic release for Mama Rose. But u

p until that last, crucial number, Pitre often sounds tentative and breathy, as if she's purposefully holding back. The score's less obviously showy songs—"Some People," "Together Wherever We Go," "Everything's Coming Up Roses"—seemed short-changed opening night, as if Pitre were saving her voice for that full-throttle endgame. And when you've cast a Herbie who isn't primarily a singer (Keith Kupferer), it hurts doubly if Rose isn't operating at full power on the Herbie/Rose duet "Small World." (That said, Kupferer's endearing, enduring Herbie is one of the most full-realized characters in Gypsy. Kupferer's big-hearted portrayal will have you rooting for him until his final heartbreak.)

As for Gypsy's stripper colleagues: They bring the house down with their exemplary bawdy gimmicks. Rengin Altay's turned-on Electra makes grinding seem hilariously perfunctory; Molly Callinan's statuesque Mazeppa is a formidable horn-blower and Barbara Robertson's demure Tessie Tura recalls Anna Pavlova way, way past her prime.

In all, the pieces are in place at Chicago Shakespeare for an exceptional revival of Gypsy. Here's hoping that Rush more fully becomes the white-hot showgirl that defined the world's most famous stripper. And that Pitre lets loose and gives clarion voice to Mama Rose's unstoppable ambition from curtain up to curtain down.