'Tis the season to take in a play or two, and Lincoln Center Theater is currently presenting four different ones in its twin houses. Three are very much worth seeing, though one is flying a false flag. Michael John LaChiusa's "Marie Christine," which opened Thursday, is billed as "a new musical," and the composer-author insists at every possible opportunity that it is, indeed, a musical, albeit a serious one. Serious it is, but a musical it isn't: In fact, LaChiusa has written a vernacular opera, and a damned good one.

"Marie Christine" is a voodoo "Medea" with a bit of "Citizen Kane" stirred in to stiffen the brew. Audra McDonald, the best singer on Broadway, plays a Creole mother of two who murders her illegitimate sons rather than turn them over to the ambitious white father (Anthony Crivello) who has callously dumped her to make a politically convenient marriage (she whacks the wife, too, while she's at it). The music is a savory polystylistic stew--Caribbean percussion, dissonant underscoring, even a show-type tune or two--and McDonald eats it up. Her performance is scorchingly bold, the kind you dream about weeks after the fact.

The advance buzz on "Marie Christine" was awful, no doubt because it doesn't live up to musical-comedy expectations: no snappy numbers, no chorus lines, no send-'em-home-happy finale. Had it been presented by New York City Opera, it would have drawn a more appropriate audience (and some of the supporting roles would have been better sung, which is something of a problem here). But if you approach it as an opera, my guess is that you'll be wowed, not only by McDonald but also by Graciela Daniele's supple, fluid direction. She's a choreographer, and it shows.

"Contact," which is billed as a "dance play," is also something of a genre-bender. It consists of three one-act plays by Susan Stroman and John Weidman that are told in dance, with some spoken dialogue but no onstage singing (the score is a batch of recordings ranging from Stephane Grappelli to the Squirrel Nut Zippers). But unlike "Marie Christine," it poses no problems of palatability, and has actually become the biggest hit of the season to date. Small wonder: Stroman's choreography is buoyantly lively, and the finale, in which a suicidal advertising man (Boyd Gaines) meets a leggy vision in yellow (Deborah Yates) at a swing dance club, is as heartwarming as an August afternoon. Yates, a new face on Broadway, is clearly bound for glory--she dances like a dervish and is also a smart actress.

Both shows are spelled on Sundays and Mondays by a pair of non-staged readings. A.R. Gurney's "Ancestral Voices: A Family Story," the latest of his chronicles of WASP melancholia, is being performed by a rotating cast. The version I saw starred Mason Adams and Mariette Hartley, who were both perfect, and was narrated by Robert Sean Leonard, one of the stars of Whit Stillman's "The Last Days of Disco" (a nice touch, since Stillman and Gurney work the same ethnic territory). It's a wry, unexpectedly poignant memory play for five voices, exactly the sort of thing John P. Marquand would have liked to have written. "Morning, Noon and Night," on the other hand, is Yet Another Evening With Spalding Gray, which is just about all that needs to be said about it. For the benefit of those fortunate Washingtonians unacquainted with his work, Gray lives in the Hamptons, spends his summers on Martha's Vineyard, listens to National Public Radio, drives a Volvo, does yoga, whines to his therapist, has affairs, obsesses endlessly about death, and writes and performs flip, ironic monologues about all these things. I found this one as smug and tedious as its predecessors--90 minutes' worth of Woody Allen without Yiddish, punch lines or an intermission--but the audience, which appeared to consist almost entirely of Bill Bradley-buttoned Upper West Siders on the night I went, purred happily as Gray caressed their collective neuroses. Me, I'd rather be dancing.