Sunset Boulevard.

Whatever you do, don't watch Sunset Boulevard, the movie, right before you see Sunset Boulevard, the musical. Billy Wilder's 1950 movie is a sui-generis classic, a Pirandellian film noir about films, in which fading silent-screen siren Gloria Swanson played fading silent-screen siren Norma Desmond, and creepy, Teutonic director Erich von Stroheim played creepy, Teutonic director Max von Mayerling. The film established a breathtakingly brazen conceit: It's narrated by cynical screenwriter Joe Gillis (William Holden), who is already dead when the story begins. In an extended flashback we observe Joe's desperate efforts to land a studio writing job, his chance meeting with Norma, their sticky entanglement, their wary wooing. Along the way come Norma's definitive lines: "I am big! It's the pictures that got small!" and "We had faces then!" (Swanson spoke with exclamation marks.) In a dizzying circle, the film ends as it began, with the murdered Joe face down in Norma's pool. Norma, completely out of touch with reality, descends the stairs of her mansion, certain that she is a star once more. "And now, Mr. DeMille, I'm ready for my close-up!" she proclaims, looming closer and closer to the camera in a mad, deluded blur.

Composer Andrew Lloyd Webber's musical can't compare. However, acknowledging that, you should, you must see Sunset Boulevard, the musical, if only to witness a state-of-the-art megashow that is not just a night at the theater, but a headline-grabbing theatrical event. Norma's monstrous mansion, Glenn Close as Norma Desmond, director Trevor Nunn's swiftly cinematic staging, some of Lloyd Webber's better songs, Glenn Close, vintage automobiles, a deft supporting cast, Glenn Close. There's a lot to take in. Sunset Boulevard is a dark-hued, macabre spectacle that Cecil B. DeMille would have appreciated.

Spectacle is the key term. There's not much subtextual meaning here; audiences won't linger over steaming espressos to puzzle out Norma's motivation, Joe's gigolo-like dependence, Max's devotion. They are all laid out in Don Black and Christopher Hampton's straightforward book and plodding, often banal lyrics. Lloyd Webber's take on the tale reveals less about life or about how others live (and, in this instance, die) than it does about what it takes to make a show a hit right now. And in Norma Desmond, Lloyd Webber has written a leading role capacious enough to encourage multiple interpretations, much like the long-running Hello, Dolly! Perverse, despairing, glorious, Norma Desmond is the Dolly Levi of the 1990s.

Glenn Close delivers, Her Norma is way over the top, with hugely theatrical gestures, histrionic line readings, and the cunning of a she-wolf. Underneath, her Norma is sad and pathetic, a woman stripped of identity when deprived of mass adulation. Close affects a strange Mid-Atlantic accent, sounding now like Katharine Hepburn, now like Claude Rains, which, if odd, is apt for the grandiose Norma. As a singer, Close powers her way through "With One Look," which details her dazzling wattage as a silent star, and "As If We Never Said Goodbye," her emotional return to the Paramount soundstages, with everything she has, which is plenty. She acts the hell out of Lloyd Webber's songs.

Her body language gives each ascent to her lair and descent to her living room a tellingly varied inflection. Full of hope, she sails up her monumental staircase with girlish glee, chin held high. Hunched over like Quasimodo, she's wretched, yet dangerously corrupt. When she finally seduces Joe, her blood-red nails slash the air in twin arcs of pent-up passion. Subtle it ain't, but Close telegraphs Norma's inner states to the last seat in the last row. Her final appearance is one for the books. Outlandishly costumed as Salome, she veers, wobbles, strides, slithers downstairs. trailing the red ribbons that once enfolded her cherished screenplay. She's a marionette tripping on her own bloodied strings. It's a great performance.

Whether it's a good performance is another matter. Close is the Energizer Bunny of actors: she emotes up a storm, she has crack timing, and when she cries those are real tears streaming down her rouged cheeks. But her effects seem calculated, distanced. She's sitting out there with us in the dark, admiring her performance almost as much as we do. Still, if Close does not evoke terror and pity, she comes as close as any actress could in Lloyd Webber's version of the story.

Director Trevor Nunn contrasts the syrupy excesses of the score with a bracingly cynical tone, and populates the stage with an eye-popping assortment of Hollywood types: cigar-chomping moguls, daffy chorines, aspiring scenarists. and related Tinseltown hustlers. He also keeps a lavish production under a tight rein; John Napier's astonishing set dominates only when it should. Sunset is not a dance show, but Bob Avian's musical staging does zap us into a hyperactive studio backlot and captures the camp of a 1950s Biblical epic in production.

It's easy to underestimate Alan Campbell as Joe Gillis. He is onstage for virtually the entire show, and he consistently rewards attention. Campbell is cast against type; with his haystack of blond hair, he looks more like a choirboy than a hard-bitten hack struggling to make ends meet, but he brings grit to his booming rendition of the title song. As Max, the great George Hearn doesn't have much more to do than glide mysteriously about and sing glowingly of Norma's former glory. Newcomer Alice Ripley brings some gumption to Betty Schaefer, Norma's rival for Joe's affections: she could have been a conventional ingenue.

Sunset Boulevard has racked up a record-breaking $37 million in advance ticket sales, so good seats should be available sometime around the millennium. If you can't see the musical, you can always rent the movie.