Once Upon a Time may be the ne plus ultra of disco albums. A four-sided, four-"act" mock opera loosely based on Cinderella, it marks another technological triumph for Munich-based producers Giorgio Moroder and Pete Bellotte and for chameleon-voiced Donna Summer, who emerges as both the Diana Ross and the Bette Midler of disco and as one of pop culture's all-time camp divas.

By blending sex and science fiction, Moroder and Bellotte have developed the aural counterparts to the visual imagery of discotheques. But the sex is of the skinflick variety, and the science fiction, pulp. Barry White's softcore bubblings seeded this erotic Muzak, and Moroder and Bellotte have brought it to full flower. Their synthesizer-based disco is the music of the brave new world—music with a capacity to suggest comic-book erotic/astral configurations, limited only by the studio and synthesizer technologies that produce and reproduce it.

Using Donna Summer as a pansexual, Barbarella-style fantasy object, Moroder's and Bellotte's camp eroticism pulls humor out of the gap between pornography's fantasy of sexual insatiability and actual human sexual capacity. Summer's first hit, "Love to Love You Baby," fused Barry White's pseudoorgasmic approach with the synthesized Eurodisco style heralded by the Silver Convention's "Fly, Robin, Fly." "Love to Love You Baby" not only paved the way toward a more blatant eroticism, it exhibited a nearly total fragmentation of narrative musical structure and signaled disco's break from short radio forms to longer, more organic structures. In their next two albums with Summer, Moroder and Bellotte padded the chant with a diaphanous gloss and fluffed out the fantasy of perpetual gratification with love-comic scenarios. I Remember Yesterday finally revealed Summer as not just a centerfold gasp but a brassy pop/soul stylist in the Bette Midler-Melissa Manchester mold. But the album's signal achievement was "I Feel Love," in which they underlined Summer's dreamy vocals with jittery, diamond-hard synthesizer rhythms accented by a whiplash.

With Once upon a Time, Moroder-Bellotte-Summer diversify even further. Three sides—acts one, two and four—feature several styles of propulsive dance music designed for disco play. But act three is mostly R&B pop and contains two of the strongest nondisco cuts of Summer's career. "A Man like You" offers a clever pastiche of Gene Page's arrangement for "Get Closer." "Sweet Romance," a pop/soul tear-jerker with a catchy tune, has Summer hilariously praying to "father dear," with a quasi-baroque harpsichord behind her.

What comes as a surprise is how the ominously surreal atmosphere of the album's best disco sections belies the light escapism of the Cinderella concept. The feverish momentum in act one's most powerful segue — "Faster and Faster to Nowhere" and "Fairy Tale High"—suggests frantic stimulation rather than gleeful excitement, with the nightmarish intensity enhanced by sped-up vocals and dissonant textures. In the first two cuts of act two—the most consistent side—a softer variant of the jittery synthesizer on "I Feel Love" punctuates an echoed chorus that responds to Summer's obsessive interior monologue and implies schizophrenia.

Could Once upon a Time be a critique of the voluptuary subculture that is sure to devour it like candy? Or is the downswing of the roller coaster just the headiest part of the kick? In his synthesized solo album, From Here to Eternity, Moroder evoked a deep, empty space beyond the erotic. Although Once upon a Time isn't so weird, it's just as cool. Moroder's and Bellotte's aural style equates glamor and shallowness with such a glacial detachment that it seems sadistic. The music reflects the tawdry, orgy-palace atmosphere—Versailles for the masses—that stands for elegance in the disco business, and then refrains from animating that atmosphere with a single drop of warmth; instead it pricks and mocks.

How could Moroder and Bellotte not be aware of the implications of their eroticized space music? Their work with Summer suggests a climate in which eroticism has been debased, exploited and placed under such close technological scrutiny that its value can only be redeemed by fantasy. But fantasy, being susceptible to commercial manipulation, can also fail; hence its elaboration to often desperate extremes. Having moved from simple orgasmic chant to Cinderella-turned-insideout in the fun house, Moroder and Bellotte seem to be tracing this fantasy cycle themselves. How much farther will they go, can they go? Of course, the fun house is supposed to be a little scary. Isn't sex more erotic when spiced with a sense of danger? But how much danger? Isn't it possible that when the fun house and the fake monsters were built, a real one got locked inside?

That's one question Once upon a Time won't answer, because like all camp, it's far too knowing to venture a straightforward opinion on anything. Like a fun house mirror, it gives back a distorted reflection, and if you don't like one, there's always the next mirror and the next.... (RS 256)

STEPHEN HOLDEN