It's frequently said that 90% of a director's job lies in the casting, and David Hyde Pierce indisputably nailed that part of the job as director of the new wedding-themed musical comedy "It Shoulda Been You."

He enlisted a cast of uniformly superb stage actors, including Tyne Daly, Harriet Harris, Edward Hibbert, Sierra Boggess ("The Little Mermaid"), Lisa Howard ("Spelling Bee"), Montego Glover ("Memphis"), Chip Zien ("Into the Woods") and Josh Grisetti ("Enter Laughing"), among others.

It's just a shame that the show itself is so dated and unfunny. When the material is this disappointing, no one can save it.

The concept is simple: We're at the wedding of a Jewish girl to a Christian boy and neither set of parents are thrilled about the match. As the bride's older, romantically unattached sister dutifully oversees the preparations, a handful of complications arise, like an overenthusiastic former boyfriend showing up uninvited, plus the sudden need for a prenuptial agreement.

About two-thirds of the way through the 90-minute show, there's a ridiculous bombshell -- which I will not spoil in this review.

Under better circumstances, this might have been a fun, feel-good trifle. Unfortunately, the sitcom humor is well-worn and hokey, the music is weak, the characters are one-dimensional stereotypes and the concept is tissue-paper thin.

Ironically, having great actors involved doesn't make it any better. Instead, you feel frustrated that they're not in a better show.

Take, for example, Grisetti, who gave the performance of a lifetime six years ago in "Enter Laughing: The Musical," which by all rights should have transferred to Broadway. His sublime comic abilities are on display here, but to what effect?

Pierce, who emphasizes the over-the-top, lighthearted tone in a clean and efficient production, might have a future as a director, but he needs to be more careful when choosing his material.

If you go: "It Shoulda Been You" plays an open run at the Brooks Atkinson Theatre. 256 W. 47th St., ItShouldaBeenYou.com.