Is there a surer route to heartbreak than to fall for another because of his or her eyes, only to discover you can never fully open your own? The couple at the center of the magnificent new musical Green Eyes is crippled by just this irony. But the aching pasts and pointed aspirations they confront in attempting to come closer together are the most liberating and enlivening New York's stages have seen yet this year.

For composer-lyricist Brian Mazzaferri, choreographer Lizzie Leopold, and director Jessica Redish have crafted a work in which its characters may revel or rebel, but may never wallow. The man and the woman they describe may share words, moments, or a bed, or may struggle to stay festering in the recalled betrayals of a hundred relationships gone wrong. But disappointments turned pained glances may never be turned inward. For that matter, emotional silences of any sort are forbidden - you can never completely escape from the one you love.

So he and she are each represented by both a singer and a dancer: Nick Blaemire and Ryan Watkinson on his side, and Celina Carvajal and Melissa Bloch on hers. The romance begins with Blaemire and Carvajal, when she discovers him playing with his band in a club, and he's transfixed by her vivid green eyes. They meet, talk, and share, entirely in songs that emanate from the gentle rock Blaemire creates, until they can no longer contain themselves.

That's when Watkinson and Bloch step in and take over, gliding across and throughout the inexpressible, weaving through the singers' subtext in ways that don't always flatter the lovers-in-the-making. Sometimes, Watkinson and Bloch blend with harmonic grace that validates the union the singers present; other times, they refute it outright, injecting fear, anger, or loss into what at first seemed like straightforward proclamations of devotion. Even their lovemaking bursts with physical uncertainties that belie the stated ecstasy: Who's really in control, and is the other even there at all?

Such questions mount as the score passes through wishful ballads, wistful pillow talk, and the tangled conversations typically presaging breakups long in the making, all lined with the passion of hot-blooded young people searching for themselves as much as they are each other. When they must, the vocals give way to underscoring so naturally, you might not notice it until Watkinson and Bloch swirl into center stage to continue the story Blaemire and Carvajal can sing no more.

The beauty of Green Eyes is that you can never be sure which art deserves precedence. When dance and song intersect, focusing merely on one duo or the other is not enough - the ways they interact (or don't) require a constant shifting of focus, lest you miss a landscape-altering sweep or lyric. This show requires constant, active participation, but it's rewarded time and again by the performers, who marshal so many interlocking feelings that determining a central performance is impossible.

Everyone is superb because of the others, because the actual (Blaemire and Carvajal) and the ideal (Watkinson and Bloch) clash so often they become indiscernible. That's just how it should be. The caresses loading Leopold's dances, the warm embraces and tremulous steps away that fill Mazzaferri's score (especially as they ripple through Matt Hinkley's terrific five-piece band), and the light-footed hopefulness of Redish's staging only further highlight this.

Taken together, they make Green Eyes the rare vest-pocket love story that's as epic in scope as it is intimate in stature. But it's also something considerably more important: musical theatre in its most exciting, elemental form.

Run Time: 1 hour 10 minutes
Tickets online, Venue information, and Performance Schedule: The New York International Fringe Festival - FringeNYC