03/30/2014 09:05 pm ET Updated May 30, 2014

First Nighter: Idina Menzel's What/If Is Extremely Iffy

Give me a minute here while I clear my head after attending last night's performance of If/Then, the new musical starring Idina Menzel. Never mind. I'll just have to confess I can't keep straight what goes on in the Brian Yorkey-Tom Kitt follow-up to their Pulitzer Prize/Tony-winning Next to Normal. I'm so flummoxed I'm even thinking of offering a reward to anyone who can fill me in.

I can explain some of it. Menzel is Elizabeth, who's just returned to Manhattan from a failed 12-year marriage and wants to start over. Meeting old friends Kate (LaChanze) and Lucas (Anthony Rapp in a park, she's offered a couple of ways to go by them. The separate roads offered Elizabeth turn into two very different lives she might inhabit. There are Liz's life and Beth's life. You see, Kate insists on thinking of Elizabeth as Liz and Lucas insists on thinking of Elizabeth as Beth. It's as if librettist-lyricist Yorkey has begun his work after reading Robert Frost's "The Road Not Taken" with its opening line "Two roads diverged in a yellow wood."

Are you with me this far? If you are, you're on your own from here on out. In Liz's life -- or is it Beth's -- she returns to her career as an urban planner and rises high in city government with the help of married boss Stephen (Jerry Dixon), who has a pash for her. (Or is that part of Beth's tale?) In Beth's life -- or is it Liz's -- she meets between-war-tours surgeon Josh (James Snyder), marries him, has two children and no time to return to her urban planning career until one of the sadder plot turns occurs.

There are plenty more road crossings -- including two(?) life-threatening situations -- as Liz and/or Beth interact(s) with Kate and her girlfriend Anne (Jenn Colella) and Lucas and his physician boyfriend David (Jason Tam). But I'm not going to wrack my brain to sort out Liz's life from Beth's for the unfortunate reason that neither story is interesting enough to make the effort, certainly not as the lame jokes about Brooklyn, Albany, Nebraska and subways continue misfiring.

But the If/Then producers, in tandem with director Michael Greif (he worked with Menzel and Rapp on Rent), have made a smart as well as a fortuitous one, it's building the show around their star, who, virtually needless to say, landed on the celebrity map playing Elphaba in Wicked and copping a Tony for it.

Critics who didn't take to the blockbuster hit (now in its 11th year) missed the obvious point that young girls saw a role model in the ostracized green witch. It's possible that those same Wicked lovers, many of them now in their late teens or early twenties, will want to see what their Idina/Elphaba is role-modeling now. (That's when she's not serving as Lea Michele's Glee mother.) Nor will it hurt that as the tuner bows, Menzel has a Top 40 hit with the Oscar-winning "Let It Go" from Disney's Oscar-winning Frozen.

Letting go is precisely what Menzel does. What might have been described as a grating voice in an earlier time is right in today's American Idol vocal range. Throughout their score, songwriters Kitt and Yorkey give their favorite belter abundant opportunities to tilt her head back, open her mouth until it resembles the looming entrance to the Lincoln Tunnel and aim piercing high notes at the Richard Rodgers ceiling.

And it's a good bet the Menzel fans (waiting to crowd behind stage-door barriers after the performance) will eat up every one of those let-it-go phrases, whether they're assiduously following the Liz/Beth journeys or not. As long as the high-powered songs keep coming, they may not even care if they do know what Beth or Liz is up to.

You can be sure that Yorkey and Kitt see that they do. The drawback is that as If/Then barrels along those two diverging paths, the songs increasingly sound alike to the extent that you wonder -- I did, at least -- how the singers know one from the next or the last. The opener "What If?" lays out the premise and is catchy and provocative, but from then on, songs about signs and surprises and moving forward blend into each other.

Perhaps one or two of them would make an impression sung away from the context. Were I to suggest a selection that other singers might want to cover, it would be the stern, taciturn "You Learn to Live Without" that Menzel sings not as Liz and not as Beth but as Liz/Beth. Nonetheless, If/Then is not a cast recording I await with bated breath.

An interesting If/Then aspect worth noting is that there's a schizophrenic element in the Liz/Beth differentiation. Yorkey/Kitt adherents may be intrigued that schizophrenia is also the subject of Next to Normal -- also directed by Greif -- in which protagonist Diana is trying to come to terms with herself, too.

Looking around for other aspects to commend, I'd say the featured players give good accounts of themselves and certainly sing as if to the AI style born. The supporting cast is often on hand to realize Larry Keigwin's choreography. Keigwin, who's had his own company for over a decade, makes his Broadway debut here. Fans will recognize his likable idiosyncratic moves and hope he's sought out for other projects.

Elsewhere, there's not much to write home about. Ticket buyers who recognize Greif's affection for multi-level steel structures will understand why Mark Wendland provides them once again, along with all sorts of revolving units that at the end of this long day only seem cluttered. There's not much to Emily Rebholz's costumes, either. Menzel mostly wears unexciting combinations of black, write or gray as both Liz and Beth. Or maybe there's a difference I didn't catch. She does get into an attractive white wedding dress for the story (Liz's? Beth's?) in which she marries Josh.

Speaking of what-ifs. What if Yorkey and Kitt had taken their strong what-if notion and produced something coherent? As is said more than once by characters about this sort of surmising, "You never know."