The best moment from the opening night of Charlie and the Chocolate Factory, the former West End/Broadway musical currently touring the US, didn’t happen on stage. The best moment was the sound of one young, fearless voice in the audience, a row or two back from where I was sitting, loudly singing “Pure Imagination” along with Willy Wonka (Noah Weisberg).

It's doubtful that many folks outside my immediate vicinity heard the spirited singing, and most of the folks that did looked visibly annoyed. But those charming, occasionally-tuneless vocals reminded this writer that Charlie—originally written by Roald Dahl in the early '60s and adapted into films, a theme park ride, a video game, and, supposedly, an upcoming animated series on Netflix—was made for kids. It was made for timid youngsters who dream of stumbling into a world where sweets are abundant, your awful schoolmates get thrown down a garbage chute or blown up like a balloon, and your thoughtfulness is rewarded rather than ridiculed.

David Grieg, Marc Shaiman, and Scott Wittman seem to have let that detail slip from view when they adapted this story for the stage in 2012. This iteration of Charlie is replete with jokes and winking modern day references meant to please the grownups in the audience and complement the few Anthony Newley/Leslie Bricusse classics that the musical retained from the 1971 film adaptation like “Imagination,” “The Candy Man,” and that ever-earwormy “Oompa Loompa Song.”

Everything else about this musical felt like it was straining to stay relevant. Violet Beauregarde (Brynn Williams) is reimagined as a gum chewing social media maven that calls herself “The Queen of Pop.” Mike Teavee (Daniel Quadrino) is now a snotty gamer with ADHD who gets stuffed with meds by his boozehound mom (Madeleine Doherty). Songs associated with these two kid characters have also been modernized to a fault—there's a decent bit of Broadway funk to introduce Violet, but an embarrassing glitch-house tune to score Mike’s televisual comeuppance.

Charlie is also hobbled by its first act, which unfolds at a languorous pace, setting up the impoverished plight of Charlie Bucket (Rueby Wood, the only actual child in the cast), and the quest for the five golden tickets to Wonka's chocolate factory. The second half is a sugar rush of hurried scenes and unsettling set pieces. There are some rather creepy squirrels that visit violence upon Veruca Salt (Jessica Cohen), and a truly unnerving chorus manipulating the tiny Oompa-Loompas puppet bodies. Better that than Dahl’s original rendering of Wonka’s workers as African pygmies, I suppose. The production steams towards what should be a rousing and joyous conclusion, but winds up limping to the Great Glass Elevator.

Poor Weisberg isn’t done any favors by this. As charming (and sweaty) as he is, he isn’t allowed the same child-like ebullience nor slightly sinister edge that made the original Dahl character and its filmic representations so memorable. Wonka lands somewhere near the manic, pop culture-saturated voice work of Robin Williams in Aladdin, but without the balance of charm and sweetness. It’s a one-note character that fumbles what should be magical moments throughout. To Weisberg’s credit, it’s hard to evoke spectacle when much of the factory sets exist only on a LED screens surrounding the stage. But a little wide-eyed wonder or a smidge of darkness around his edges would have done wonders for this candy-colored sour ball of a musical.

(Playing Tues Aug 13– Sat Aug 17, 7:30 pm, Sat Aug 17, 2 pm & Sun Aug 18, 1 pm, 6:30 pm, Keller Auditorium, 222 SW Clay, $25-85)