VANCOUVER, B.C. - If "Phantom of the Opera" was a musical about a chandelier, then composer Andrew Lloyd Webber's blockbuster follow-up, "Sunset Boulevard," is a musical about a swimming pool and an extremely long, gaudy staircase.

Actually, thanks to some splendid source material, the $8 million production of "Sunset Boulevard" making its Northwest debut at the Ford Centre for the Performing Arts in Vancouver, B.C., occasionally threatens to be something beyond an excuse for eye-popping scenic effects and a schmaltz-drenched score - though it has those accoutrements, plus a spectacular staging by an epic-musical-specialist director, Trevor Nunn.

Like the memorable 1950 film by Billy Wilder which the Don Black-Christopher Hampton book and lyrics are closely based on, this multiple Tony Award winning show conveys an opulent noir morality tale set in Hollywood at its most seductive and perverse. Unlike the movie, however, the stage version sometimes sweetens the acidic tartness of the fable with the kind of glam-sham romanticism Wilder was slyly sending up.

"Sunset Boulevard" actually has more in common with Lloyd Webber's highly profitable "Phantom of the Opera" than superior stagecraft and a penchant for recycling a few overbearing melodies ad infinitum. The ultra-romantic "Phantom" drummed up sympathy and repulsion for a deformed but amorous male demon dwelling in the bowels of the Paris Opera House. "Sunset Boulevard" promotes our love-hate relationship with a movie-queen gorgon hiding out in a Tinsel Town mansion. These two monsters are flip sides of the same mythic coin - but "Sunset" is more intelligent nonsense, and offers a rare showcase for mature stage divas.

In London, the diva playing Norma Desmond was Patti LuPone, on Broadway it was initially Glenn Close, and in Vancouver it is veteran actress-singer Diahann Carroll, who also starred in the show's lengthy Toronto run.

At 63, Carroll has a few years on Desmond (who is allegedly a hopeless has-been at 50) but you would never guess it. She looks altogether smashing sashaying around in Anthony Powell's to-die-for array of beaded, brocaded, fur-trimmed gowns and satin turbans. Singing the show's pair of signature narcissistic ballads, "With One Look" and "As If We Never Said Goodbye," Carroll's voice remains firm and forceful. And she gives the predatory Norma real allure, along with an aura of touching fragility.

That is quite different , and less vivid, from Close's Tony-honored approach. Close (like Gloria Swanson, the movie Norma) created a grotesque, almost vampiric figure - pathetic in her grasping desire for Joe Gillis, the cynical young screenwriter whom fate deposits at her lair one night, and sadly delusional in her belief that mogul director Cecil B. DeMille would soon restore her stardom, yes. But also a personality so distorted by her years in the Dream Factory that she finally can't distinguish between playing the murderous Salome and being her.

With Carroll's more vulnerable and sympathetic portrayal, "Sunset Boulevard" loses much of the morbid campiness at its deliciously wicked core. Some sense of irony is preserved, however, in Rex Smith's inspired Joe Gillis. Smith's boyishness-gone-to-seed good looks, his hearty singing voice and his flair for boisterous self-mockery keep the show from bogging down in melodrama more than once. He never lets us forget that Joe is striking a Faustian bargain by becoming the script doctor and boy toy of a rich wacko. And the guilty, cocky shrug he gives, while lolling by Norma's pool in the snazzy new suit she's bought him, says it all.

The show's two major supporting roles are well-filled. Walter Charles (known in Seattle for his sterling work at the 5th Avenue Theatre) has the grim Teutonic efficiency of Norma's butler Max down pat, and sings his heart out in the worshipful, "The Greatest Star of All." And Anita Louise Combe gives a charming account of Betty, the wholesome script girl who becomes Norma's unwitting rival.

As for the production enfolding these performers and a large, busy chorus - well, if it ain't Cecil B. DeMille, it's close. John Napier's mammoth sets fade in and out to striking montage effect, creating a bipolar Lotus Land: Norma's absurdly rococo villa (which has enough gilded kitsch bric-a-brac to stock several Las Vegas casino showrooms), and the equally surreal environs of a Hollywood studio complete with a fabulously vulgar set for a biblical epic.

Andrew Bridge's lighting scheme features marvellously spooky shadow effects. And especially in a whiz-bang car chase scene that seamlessly blends film footage with live action, and a couple of ingenious split-level scenes with two tiers of action, Bridge's contributions enhance Napier's stunning work - as does the eerie swimming pool image that opens the show.