The best thing that can be said about "Pippin," the Stephen Schwartz musical that had its boisterous, clackety opening over the weekend at Mixed Blood Theatre in Minneapolis, is that it has enthusiasm and heart. If only those qualities were enough to help it realize its lofty ambitions.

Under-rehearsed and unpolished, the show's staging is flawed.

"Pippin" is the second production of Theatre 55, an inclusive company co-founded by Richard Hitchler, the former artistic director of SteppingStone Theatre for Youth. He is serving the other end of the age spectrum now with an outfit dedicated to "enriching the lives of elders as artists, audiences and lifelong learners."

That idea gets translated into casting as many people as possible even if they are not the right fit for a role. "Pippin" has a dancing, singing cast of 17, and they are clearly enjoying themselves, including with hula-hoops. (Sandy Augustin did the playful choreography.)

The company burst onto the scene a year ago with a splashy production of "Hair," the generation-defining hippie musical that has traditionally been cast with much younger actors. But Hitchler's "Hair," he declared proudly, was "by people who lived it."

"Pippin," too, has been aged up a bit. It used to be about a young prince's search for meaning. Now in this Theatre 55 reconception, a middle-aged prince is having a midlife crisis.

Brent Berheim is an odd choice for Pippin. He's not much of a singer, struggling as he does with pitch and key and stuff like that.

His Pippin is whiny and flaky and flip. The character feels less like an adult reverting to some earlier stage and more like someone who never left adolescence.

"Pippin" has Brechtian distancing effect and metatheatrical elements. The show is notable for several historical reasons. Legendary director and dance-maker Bob Fosse staged and choreographed the 1972 original, leaving his imprint on the work and setting a high standard that was partly matched by Diane Paulus' 2013 Broadway revival.

Ben Vereen and Patina Miller both won Tonys for playing the Leading Player. In Hitchler's vision, that role is inhabited by a trio of black-and-red, leather-clad performers (Patty Lacy, Lisa Ramos and Beverly Tipton Hammond). And the whole ensemble is backed by a thin four-piece band.

In addition to casting being off, and the conception being flawed, the show is not fully baked. The music sounds like it could use more polish. Ditto for the actors, who had not cohered by opening night.

And the voices, really, don't go well together. That's partly because of the amplification. Some mics are clear. Others are not.

There are hints of what the show could be. Lola Watson, who plays naughty grandmother Bertha, is a highlight with "No Time at All," which becomes an audience singalong.

And the one place where everything comes together is at the very end. That's when the music is delivered without amplification, and the voices finally meld into something that's hauntingly beautiful.

Twitter: @rohanpreston