To walk into an opera house is to defy both the hyperelitist strictures of Samuel Beckett (who called it “a hideous corruption” of music because it imposed the specificity of language on an abstract and “immaterial” flow of notes) and the Bronx cheers of Bugs Bunny (nobody who’s ever seen “What’s Opera, Doc?” will ever get rid of the image of Bugs with Brunnhilde’s braids). And last week it felt particularly distracting to walk across the plaza of Manhattan’s Lincoln Center and toward the Metropolitan Opera. They’ve hung giant post-September 11 American flags from the clean-lined, optimistically pre-postmodern white buildings, and to anyone who’s been following the news reports, the place looked forlorn. New mayor Michael Bloomberg has strongly suggested that the plans for $1.2 billion worth of renovations would have to be postponed–the city just can’t afford the contribution former mayor Giuliani promised–the center’s top management has been turning over like the government of Argentina, and Beverly Sills, 72, the charismatic, donor-friendly ex-Met prima donna who’s headed the center for the past eight years, announced she’d soon retire.

But I doubt that many minds wandered to any of this stuff for long during the four hours of the Met’s new production of Richard Strauss’s “Die Frau ohne Schatten.” It does what opera does best: dissolves all such considerations in its own sublime irrelevance. It’s an artifice that domesticates human pain and passion, that alludes to and improvises upon the world that’s too much with us, but never lets the real deal come within a country mile. This isn’t to say that “Die Frau ohne Schatten” (“The Woman Without a Shadow”) is up there with opera’s great indispensables, like “Don Giovanni” or the Ring cycle. The Strauss scholar William Mann calls this work, first performed in 1919, “perhaps the most pretentious in operatic history”–which is going some–even while acknowledging that it’s probably the most “beautiful and moving” of the collaborations between Strauss and the librettist Hugo von Hofmannsthal.

The story (believe me, you don’t want a plot summary) is a bunch of symbolist twaddle involving the Empress of the spirit world who has to acquire a mortal woman’s shadow before her husband turns to stone. Or something. Hofmannsthal intended it as a sort of modern “Magic Flute,” with its doppelganging pairs of high-low lovers, its make-it-up-as-you-go mysticism and its ultimate triumph of altruism and love. But it’s also a sort of anti-“Parsifal”: Wagner’s last masterwork was a propaganda piece for sexual purity, while Strauss sets Hofmannsthal’s propaganda on behalf of marriage and children to consciously Wagnerian music. That music is a stoner’s fantasy: lush and variegated orchestral textures and colors, utterly enjoyable and bafflingly unmemorable. Strauss himself said his heart was “only half in it,” that he couldn’t fill Hofmannsthal’s emblematic characters with “red corpuscles,” and that his wife found the final quartet “cold,” and without the “heart-touching flame-kindling” oomph of the great trio he wrote for “Der Rosenkavalier.” The Met never gave “Die Frau” a production until 1966, and nobody seemed to miss it much.

Paradoxically, the opera’s very limitations help make the Met’s current version thoroughly transporting. Any soprano or tenor who sings in tune can make you savor again a shapely and passionate old favorite–Bellini’s “Casta diva,” Puccini’s “Donna non vidi mai”–but Strauss’s noble amorphosities need the intensity and tonal richness of a Deborah Voight (the Empress) and a Thomas Moser (the Emperor) to make them convincing. Voight sometimes sounds amorphous herself–at least to my ears, her powerful upper register can white out into gorgeous notes of indeterminate pitch–but she sings like a hot angel in “Die Frau,” especially in the third act. The German soprano Gabriele Schnaut, as the Dyer’s Wife (the downtrodden slum-dweller who has the coveted shadow), even outsings Voight, but of course she benefits from having the earthier and more likeable of the lead soprano roles. The German mezzo Reinhild Runkel gives a chilling sense of malice and menace to the sinister Nurse (a black-clad, white-faced figure of sexual repression and general marplottiness). And the German baritone Wolfgang Brendel makes Barak the Dyer (think Pappageno as working stiff) into a warm and sympathetic figure. Only feminist resentment–for Hofmannsthal, a silly, unnatural aberration–and adulterous temptations engineered by the Nurse could keep the wife out of bed with such a thoroughly good guy until the end of Act III.

But at least as much credit for transmuting a balky and eccentric work into a timeless four hours of opera belongs to guest conductor Christian Thielemann, musical director of Berlin’s Deutsche Oper, a magician who gets the Met orchestra to disappear into the music–this is a compliment, by the way–and to Herbert Wernicke, the German director and designer making his American debut. Wernicke’s sets, costumes and lighting play artfully with the parameters of belief and disbelief. His spirit realm is a long, receding hall of mirrors which, thanks to hocus-pocus involving lights and scrims, becomes a green-gray chamber of stone or a glaring red box from which there’s no escape. Then all this rises up into the flies to reveal Barak’s home: a dingy factory loft complete with a Weber-like gas grill that flares up alarmingly, and from which the Wife imagines she hears the voices of her unborn children. There’s also a cruddy old refrigerator, by the light of whose open door Barak sits gloomily at the end of Act I, as the watchmen walk above singing about the delights of marriage and children. In the Act III finale, Wernicke artfully drops the artifice and has his four singers hold forth beneath a massive bank of stage lights, their cables twisting and dangling. And he gives an ironic wink-and-nod to the old conventions of operatic spectacle. At the very end he lets the Falcon (mimed by Erico Villanueva, sung by the aptly named Julia Faulkner) flap across the stage on wires; and in Act II he has the Emperor ride across the stage on a wonderfully gratuitous live white horse.

True, not every little detail in this production works perfectly. The cool triangular mirrors the characters tote around get smeared with fingerprints by the opera’s end–where’s the Windex?–and a few times you see Voight’s shadow despite the ingenious lighting. Near the beginning of Act II–at least in the performance I saw–Moser abandons his bow and dagger at the front of the stage and we stare at it for the rest of the act, even when we’re supposedly back in the slums with Barak and the missus. Such mini-imperfections might mar a movie, whose aim is to make us suspend our disbelief unconditionally. (Some sharp eyed fans of “Lord of the Rings,” for instance, claim to have spotted a car briefly zipping through Peter Jackson’s Middle-Earth.) But in opera, you almost can’t lose. Even the major screwups that sometimes break the frame–pratfalling sopranos, pooping livestock, malfunctioning machinery–have become part of its history and mystique, since the frame is never really meant to convince you anyway. As much as any art form, opera invites a playful doublemindedness: the producers and performers pretend they’re getting you to suspend your disbelief, and you pretend they’re succeeding. Only sometimes they do succeed, and sometimes you do believe. “Die Frau ohne Schatten” worked for me. The only thing I truly couldn’t believe was that it was over so soon.