DESPITE their unforgivable neglect by the Irish theatrical establishment, the plays of John B. Keane have thrived on Irish stages for almost 50 years.

Repeatedly dismissed by the critics as overcooked melodramas, or rejected outright for their often overtly religious content, they have still managed to carve out a place in the Irish collective consciousness. Works like Sive, The Field, Big Maggie and The Year of the Hiker are as well known and enduring today as the most beloved rebel ballads.

Sive, which opened the Irish Repertory Theatre's new season last week, is a perfect example of both the strengths and weaknesses of Keane's playwriting. His first produced play, originally staged in 1959, Sive is the thoroughly atavistic tale of a tragic conflict between the generations that is as familiar in its own way as a work by Sophocles.

In language as rich as a French casserole, Keane introduces us to his young heroine, a woman who is being forced into a marriage against her will. The match, we learn, will line the pockets of the matchmakers, and if it breaks the young girl's heart they are unconcerned.

In the role of Mena, Sive's malevolent guardian, Fiana Toibin crackles with almost electrical intensity as the embodiment of human wickedness wrapped up in a veneer of righteousness. Toibin's performance is quietly exhilarating, as she senses an opportunity to rid herself of the two women whose presence is affront to her advancing age and her childless marriage to her well meaning but feckless husband Mike.

The struggle between these three women - the maiden, the would be mother and the old crone - is as elemental and mythic as a Greek tragedy or a medieval folk tale, which explains its enduring power. Keane had a genius for observing and enacting the generational struggles of the Irish in his works, and in this play he gives full rein to that considerable awareness.

In the playbill, director Ciaran O'Reilly notes that Keane's rural territory has been traversed by more recent playwrights like Martin McDonagh, but the latter's call and response pantomimes are no match for Keane's folk tales.

Watching adults speculate and strategize how best to offload an unwanted child onto an undeserving suitor is, as it should be, a horror show. Mena and her cohort, the half-vagrant town matchmaker Thomasheen, plot and cackle at their own ingenuity without a moment's thought for the young life they're sacrificing.

In the latter role Patrick Fitzgerald gives vent to a cold-hearted Machiavellian nature that has no time for love or other "high notions." For Mena and Thomasheen, the long struggle to live in an impoverished rural town has divested them both of all pretence at civility; they simply want the suitor's money for the human goods they're trafficking. Mena is so manipulative and effective at it that she almost convinces herself that she's acting in the best interests of her ward.

In the role of Sive, actress Wrenn Schmidt has hard work to wring life from what is essentially a damsel in distress role. We learn early on that Sive's parents are dead, and that cruel Mena wants her out of the house by marrying her off to the lecherous old ogre Sean Dota (played by Christopher Joseph Jones), a rich old wanton who lives in the nearby town.

Objecting to this absurd May-December wedding is Sive's grandmother Nanna and her true love, the virile young Liam Scuab, both of whom become the moral center of a thoroughly amoral tale. The cruelty of her fate leaves Sive sobbing her heart out at the unfairness of it all, and the story builds to a tragic climax.

Interestingly, Keane's dramatic instincts led him to include a pair of gypsy musicians into the proceedings to highlight and underscore the conflicts of interest that give shape to the play. Performed by Donie Carroll and James Barry, their presence adds immeasurably to the work, aiding both the theme and the setting.

The denouement, when it arrives, reminds us what a terrible thing it is to sacrifice what's best in our own natures for a financial profit that may prove fleeting.

Ciaran O'Reilly understands that Keane's chief concern is to show how human greed can blind decency, and in this thoughtful production he allows his actors the scope to discover it.

(Sive plays at the Irish Repertory Theatre, 132 West 22nd Street in New York, until November 11. Showtimes Tuesday-Saturday at 8 p.m.; Saturday and Sunday at 3 p.m. Visit www.irishrep.org.)