For a successful musical spoof to fire on all cylinders, everyone must understand the original material and the spoofers must be awfully good at what they do.

At Manoa Valley Theatre, "Forbidden Broadway" frets and coughs through its first act, and doesn't start to run steady until it connects with its "Les Miz" material in Act 2.

There's some hope midway into Act 1, when Tricia Marciel essays "Time to Say Goodbye to Sarah Brightman" and the rest of the cast gets into a Four Seasons parody, "Walk like a man/Sing like a girl." But the production fails to ignite and sputters to its first curtain by resuscitating a thin take-off on "South Pacific."

The show reaches its high point when Guy Merola — in full Jean Valjean regalia — falls to his knees for "Bring It Down," a cleverly understated plea to lower the register on those wonderfully high notes a performer must hit during "Bring Him Home."

The production also literally hits its stride as the cast marches through the themes of "Les Misérables" to create the illusion of a rotating circular stage. Marciel takes a texting break when the turntable gets stuck for a delicious "On My Phone," and the entire cast laments the prospect of aging during a show that will run forever — "Ten Years More."

While the remainder of the production is never again as good, Jaq Ryan Galliano does nice work with "Circle of Mice," a smarmy piece about Disney taking over Broadway with musicals overrun by puppets and manufactured from featured cartoons.

Kelly Fitzgerald's best moment happens in the finale, when she comes close to capturing the famous Ethel Merman vibrato. But to identify the other icons in the finale, you will have to check your program notes.

The evening is directed by Elitei Tatafu Jr., choreographed by Katherine Jones, and costumed by Dusty Behner. Much of its fun comes from watching the quick costume changes.

Subtitled "Special Victims Unit," a running gag bumps off over-the-hill and failed performers, gangland style. But while there are several potential suspects, the mystery of "who killed the show?" is never solved.

The biggest puzzle is the sound. With only Kenji Higashihama at the piano, the singers don't need much amplification for the intimate cabaret audience, but they must have some help. On opening night, the mikes seemed to be turned off. And when new lyrics to old melodies aren't immediately understood, the audience gets lost.