Please pardon the pun, but there's only one way to describe the Animus Ensemble's cross-cast production of Once Upon a Mattress, now playing at the Plaza Theatre at the Boston Center for the Arts: Ballsy.  Director John Ambrosino has pushed the core joke of the show to the limit: now when Prince Dauntless sings that he's "in love with a girl named Fred," the irony isn't that his beloved is somewhat masculine —his beloved is an actual man!

The gay marriage edition of Once Upon a Mattress was bound to happen sooner or later, and there could not have been a more skeptical audience member than I before the show started.  With gay anthems from Cher and Madonna playing on the PA and a hot pink set design by Andrew Haserlat looking more Taboo than Camelot, I braced myself for the worst.  The opening number featured a Minstrel portrayed by Stefanie Tovar as a butch dyke performance artist.  This, I thought to myself, is going to be a very long night.

And then something magical happened.  The stage flooded with fresh-faced young performers in modern dress carefully put together with some clever touches by Katie Sikkema. And backed by a band sounding much bigger than their numbers should allow (under the baton of Gary Durham), the company sold "Opening for a Princess" as the tuneful, funny song that it is.  Despite the modern dress, the clubland set, and Josie Bray's choreography (unfortunately influenced by Wayne Cilento's Wicked moves), the number worked.

And the show kept working.  For, despite any political posturing Ambrosino might claim to be doing, at heart he (and, apparently, the rest of the Animus Ensemble) is just a big ol' musical theatre queen, and I mean that in the best way possible.  Rather than directing the show to comment on the material, as the directors of both the recent television incarnation and the slightly less recent Broadway revival did, he infused his actors with the greatest gift a director can give: trust in the material.  So, by the time Brent Reno shows up in Esther Williams drag as the anything but "shy" Princess Winnifred, it doesn't matter that the princess is being played by a man.  What matters is that the princess is being played by an actor who isn't afraid to make the comedy as broad as can be while keeping the emotions of the love story honest and believable.  His impeccable timing and solid belt don't hurt either.

Reno sets the bar high with his performance, moving instantly from madcap to touching.  But he's matched by the other leads, from Kate deLima's hilarious mile-a-minute Queen Aggravain to Todd Sandstrom's sweetly dorky Dauntless.  Ariel Heller provides a solid legit sound to Sir Harry, although he's somewhat upstaged by his Lady Larkin, Erin Tchoukaleff, who is about as ideal a soubrette as musical theatre could demand.

There are a few rough patches in the show, mostly centered on the secondary characters of the Jester and the Minstrel.  The material for these characters is tenuously connected to the main story at best, and this production offers no solution to this problem, although there is a spectacularly bizarre attempt to make the song "Very Soft Shoes" work that has to be seen to be believed.  I won't spoil it for you here.

Still, the missteps are few and far between, and the rewards of this production are many.  As the opening (and closing) number says, a genuine princess is exceedingly rare.  I'd add that a relatively new theatre company with such a solid understanding of what makes musical comedy work is even rarer than that.  Don't miss this one!

Once Upon a Mattress (Music by Mary Rodgers, Lyrics by Marshall Barer, Book by Jay Thompson, Dean Fuller, and Marshall Barer)  in the Plaza Theatre at the Boston Center for the Arts, 527 Tremont Street in Boston, now through June 24th. Tickets are $33.50 - $38.50, with student and senior discounts available. For tickets or information, call the Box Office at 617-933-8600 or visit the Calderwood Pavilion box office, 527 Tremont Street, or visit one of these websites: www.animusensemble.org or www.bostontheatrescene.com.

Be sure to check the current schedule for theatre in the Boston area.