Updated

NEW YORK -- Giving a blank check to Bono, The Edge and Julie Taymor to create a musical seemed like a brilliant idea, once upon a time.

U2's worldwide success and the director's track record ("The Lion King") meant that their "Spider-Man: Turn Off the Dark" could have rebooted Broadway the way "The Dark Knight" galvanized Hollywood's superhero films.

But then the show, once scheduled to officially open Tuesday, went awry. A snowballing budget, broken bones, a concussion, multiple delays, rewrites... and what do we get? An inconsistent, maddening show that is equal parts exciting and atrocious.

On one level, the story follows the Marvel Comics canon: Dorky high-schooler Peter Parker (Reeve Carney or Matthew James Thomas, depending on the performance) is bitten by a mutated spider and acquires superpowers. He struggles to win girlfriend Mary Jane Watson (Jennifer Damiano) and battles the wicked Green Goblin (Patrick Page).

To that familiar canvas Taymor and co-author Glen Berger added twists of their own, with varying degrees of success.

Four smart-aleck teens -- the Geek Chorus -- provide a running commentary that quickly becomes grating.

Another new character is the spidery mythical figure Arachne (T.V. Carpio). Pulled from the depths of Greek mythology, her role is confusing. Is this webslinger real or merely a figment of Peter Parker's dreams? Why and how does she come back from wherever she was, and why does she leave again? Inquiring minds would want to know, if only they cared.

Then again, Arachne gets the single best number, "Behold and Wonder," only a few minutes into the show. As a way to recount her origins, five performers swirl in the air, suspended by saffron-colored sashes as strips of fabric are woven up behind them. The effect is both deceptively simple and visually enchanting.

But then it ends, and we are suddenly thrown into Peter's high school, with what looks like the cast of a road show of "Grease" executing banal hip-hop choreography.

So this erratic musical goes, constantly seesawing between the galvanizing and the lame.

The first act holds it together because it follows the Marvel mythos, but when Taymor's id takes over after intermission, the story goes out the window. You will not soon forget -- hard as you may try -- a preposterous number featuring Arachne's spidery minions and their stolen shoes, or the supervillain runway show that introduces another new character -- Swiss Miss, the lovechild of Alexander McQueen and a Home Depot.

And so it goes.

A breathtakingly beautiful scene is followed by a laughable one. The flying sequences can be thrilling, as when Spider-Man first takes off over the orchestra; other times, they look barely good enough for Six Flags, the harnesses making the movements clunky.

High-tech CGI projections are juxtaposed with such cheap effects as cardboard cutouts and Spidey shooting off Silly String.

Taymor could not decide what decade it was, so she went for all of them. The Daily Bugle scenes look as if they are set in the 1940s, the villain's lab is out of a 1960s sci-fi B movie and there is talk of the internet.

Fortunately, the score has its moments. Though Bono and The Edge seemingly recycled a few old lyrics and riffs, they have also written some solid pop songs. The best are performed by Peter and Mary Jane, and they soar with U2's trademark grandiose angst.

The rock-trained Carney -- whose brother, Zane, plays guitar on the side of the stage -- gives his numbers heartfelt passion; Thomas, the matinee Spidey, is the better actor. Damiano creates an appealingly spunky Mary Jane -- and she is in great voice -- while Page is crowd-pleasingly cartoonish as the Green Goblin.

But in any Taymor spectacle, the performances are almost beside the point: It is all about creating magic and transporting the viewer.

Here, as impressive as the flying is, the wires are all too visible. They are meant to make the characters soar, but they keep the audience tethered to the ground.