MUSICAL'S JUST TOO GOOD TO BE TRUE.

Byline: Evan Henerson Theater Critic

SOMETHING kind of astonishing happens when the four actors playing Frankie Valli, Bob Gaudio, Tommy DeVito and Jimmy Massi first sing together as the Four Seasons: ``Jersey Boys,'' aka the Four Seasons story, turns into a real and exciting rock musical. And for director Des McAnuff (himself a musician and the director of ``The Who's Tommy'') there is no ground more solid.

We get that debut song, ``Sherry,'' nearly an hour into ``Jersey Boys.'' Up till then, the score of the new musical by Marshall Brickman and Rick Elice (with music by Gaudio) consists largely of era standards or pre-Seasons nonhits. Once the Seasons as a group are in full swing, the score and the material are largely in harmony. The performance chemistry among Christian Hoff, J. Robert Spencer, Daniel Reichard and David Norona as Valli is that good.

Brickman tosses the narrative, hacky-sack-like, among the four band members. DeVito (Hoff), the group's hustling bad-boy founder, lived hard and nearly gambled the Seasons into oblivion. Gaudio (Reichard) tasted success as a teen and nearly became a one-hit wonder before hitching his star to Valli. Enigmatic Massi (Spencer), a neat-freak eccentric, quit the band early, and Valli was clearly born to be a front man and not an ensemble player. The backdrop - a series of chain-link fences and Lichtenstein-ian posters - is the neighborhoods of Jersey, a rough-and-tumble terrain where shady characters and handshake deals (``a Jersey promise'') are the norm. Even in the '60s, Tony Soprano would have been right at home.

The personal drama - interspersed with songs serving as benchmarks - becomes more interesting as the show develops. We actually get to observe Norona's Valli becoming first an adult, then a leader. The female characters, played by three actresses, are largely window dressing.

It's the musical numbers (most notably of hits like ``Walk Like a Man,'' ``December, 1963'' and ``Can't Take My Eyes Off of You'') that get this piece sizzling. Musical director Ron Melrose makes exciting use of Steve Orich's orchestrations. Many of the cast members are musicians. What they can't do for themselves, Melrose's off-stage band ably fills in.

``Jersey Boys'' has Broadway hopes. If it moves, McAnuff should make every effort to keep this ensemble together. The Four Seasons may have survived a breakup. Without this foursome - Norona in particular - ``Jersey Boys'' may not be nearly so fortunate.

Evan Henerson, [phone]

evan.henerson(at)dailynews.com

JERSEY BOYS - Three and one half stars

Where: La Jolla Playhouse, 2910 La Jolla Village Drive, La Jolla.

When: 8 p.m. Tuesday through Friday, 2 and 8 p.m. Saturday, 2 and 7 p.m. Sunday; through Jan. 2.

Tickets: $44 to $75. Call [phone].

In a nutshell: ``Oh, what a night!'' indeed. The story of a band more than an era, with excellent music and superb ensemble chemistry.