We do not seem to be able to uncover our pop megastars these days without finding utter enigmas, a la Prince and Michael Jackson.

Which is why it's nice to have Madonna Louise Veronica Ciccone around. In this case, literally: She's at Merriweather Post Pavilion on Saturday.

With Madonna, what you see is what you get, and if you miss the point of her you're missing the obvious. She is the proverbial good time had by all.

But she's calling the shots.

There is precious little mystery about Madonna, even though the details may be sketchy. It's not just that she's a self-proclaimed "Material Girl" living in a material world, a pragmatic sentiment frequently dismissed as mere ironic manipulation. It's not that she's reveling in the very fame that threatens to obliterate her charm. It's not even that she seems driven by blonde ambition.

It's that she is so unashamed of it all.

Two years ago Madonna was just another blip on the horizon. A year ago she was an intriguing presence. Now she's sold 16 million singles and albums, had No. 1 pop hits with "Like a Virgin" and "Crazy for You," made a stunning film debut in "Desperately Seeking Susan" and embarked on a national tour that establishes her as the hottest musicultural item since Prince, Michael Jackson, Bruce Springsteen and so on, inexorably backwards.

(The only problem with going uphill so fast is that the downhill slide may be much slower. No problem -- although her current "Virgin Tour" is her first, Madonna is already hinting that she's not that much longer for rock 'n' roll, that her future is in front of cameras, not crowds.)

We are, by now, getting used to this supernova effect, this phenomenon of sudden and searing exposure. But Madonna makes it look easy. Dripping with self-confidence and cloaked in obviousness, she seems to the manner born. Her music was originally geared toward urban dance clubs, and there is a facile exuberance to it even now. It is not deep, and certainly not important or meaningful, but it is easily accessed.

More significant is the fact that Madonna, in true "Outer Limits" style, controls the horizontal and vertical. In a rock tradition that dates back to Elvis Presley and runs to Prince, Madonna is a relentless self-inventor. But unlike Presley, whose spark was quickly muffled by Col. Tom Parker, and unlike Prince, who is so busy exorcising his demons, Madonna is in total control, and that makes a lot of people -- men in particular -- uncomfortable.

Her calculations may not endear her to those who are factored out, but the essential truth is that no one has backed Madonna into any corners. Her videos may be sexist or sexy, but they are her own creations. Her songs may suggest the triumph of selfishness, but she has chosen them. Her fashions and her performance may be libidinous, but they are not demeaning.

Madonna's images are her own, and she presents them with a take-it-or-leave-it attitude that leaves plenty of room for vacillation. In the video for "Material Girl," she wears a knock-off of the dress Marilyn Monroe wore while singing "Diamonds Are a Girl's Best Friend" in "Gentlemen Prefer Blondes," which imbues the song's parody of yuppie values with an ironic subtext.

Madonna never suggests she's been had, in either the biblical or rhetorical sense. Like Susan, she does as she pleases, an insouciant, guiltless and guileless free spirit. To dismiss her as so much rock 'n' roll koochie-koo is unfair. She's yummy -- young upwardly mobile Madonna -- and she's simply going about the business of being herself.

"I'm tough, ambitious and I know exactly what I want," she told People magazine a while back, and it is this most American Dream that seems to be held against her.

Truth be told, Madonna is not overwhelmingly talented as a singer, as a dancer or as an actress. But she sure does carry herself well, and seems to be a natural comedienne along the lines of her heroines -- Monroe, Carole Lombard, Judy Holliday. In this time of creative reductionism and utter vidiocity, when force of personality substitutes for depth of creativity, that is apparently enough. A well-crafted image has become more important than well-imagined craft.

At 26, Madonna has just racked up her seventh Top 20 single in 17 months (it took Streisand 17 years to do the same). She is a relative virgin in the music business, and what galls her critics -- and may very well inspire her fans -- is that her dues-paying has been as minimal as her talents have been elusive.

To make matters worse, there have been accusations, mildly disguised, that Madonna slept her way to success, shattering fragile (male) egos every step of the way. She has passionately rejected such notions, while conceding the thin line between pragmatism and insensitivity. Oddly enough, similar accusations could be, but seldom are, leveled at many male stars. And chances are that everyone Madonna charmed was just as anxious to charm her.

Little wonder, then, that she refers to herself as "the girl they hate to love," a typical Madonna spin on a familiar cliche'. But, like her alter-ego Susan, Madonna seems totally unaffected by waves of adversity. In fact, one of the key lines in that precious film could well serve as her motto: "I can take care of it."

At this point, Madonna needs some essential redefinition, to the degree that it's almost easier to point out what she isn't than what she is.

For instance, Madonna should definitely not be confused with Sheila E. or Apollonia or Vanity or the Mary Jane Girls, despite a shared passion for lacy underthings. Nor is she ready for induction into the Bimbo Batallion headed up by Terri Nunn of Berlin and Dale Bozzio of Missing Persons.

Despite their protestations, and in the case of Sheila E. some credible talent, those women are an '80s variation on the '60s girl-group tradition, with its attendant manipulation and exploitation by male producers. In the 20 years separating the Ronettes and the Mary Jane Girls, the sexual activism has become more open, but the social passivity remains the same. Bimbos suggest that their purpose is to fulfill men's fantasies; Madonna suggests her purpose is to fulfill her own.

She's also not the slut-rocker or beat-conscious sex kitten that some have labeled her. Confusing Madonna's penchant for lingerie, bare midriff and see-through smiles with sluttish behavior is as misleading as using the fact of undressed, semidressed and exotic/erotic fashion models to typecast many glossy magazines as pornography.

But what does Madonna's image tell us?

A surprising amount of analysis has gone into her custom-made "Boy Toy" belt buckle, or "unchastity belt," without anyone hitting on the possibility that it describes not Madonna, but an attitude: Boy as Toy, with Madonna doing the Toying. In ways that feminist critics dismiss, Madonna is saying that women don't need to play the waiting game with men. She is aggressive and controlling, coming on strong with a posture that's frightening to males and instructive to females who can get past the surface.

Rock is still a male preserve relatively unaffected by the gains of feminism. All too much of it is blatantly misogynous, a reflection of the unresolved sexual conflicts central to its core audience of adolescent males. Little wonder, then, that Madonna's aggressive femininity is as uncomfortable as it is uncommon, or that she's experiencing the kind of backlash seldom visited on male performers who trade on their sex appeal.

Madonna's definition of girls just wanting to have fun may be a bit more explicit and a bit less good-natured than Cyndi Lauper's, but it's ultimately just as positive. What gives them both credibility with young fans, and female fans in particular, is the combination of rebelliousness (evidenced most clearly in fashion) tempered with self-definition.

Until the mid-'70s, women rockers were basically submissive. There were no good role models in the rock tradition (Connie Francis? Linda Ronstadt?) and precious few in pop music outside the singer-songwriter context. That changed with the Go-Gos, Lauper and Chrissie Hynde of the Pretenders, who in varying degrees seized control of their careers to the point where Hynde could get a measure of revenge on her ex-husband, head Kink Ray Davies, in "Pack it Up": "Furthermore, I don't like your trousers/or your appalling taste in women/And what about your mind, or your insipid record collection/your dull home video center, the usual pornography . . . " And, from Madonna's "Material Girl": "The boy with the cold hard cash is always Mr. Right."

This is a long way from "Where the Boys Are," though some are disturbed by the distance between the self-discovery of writers as diverse as Joni Mitchell and Hynde and the self-absorption and self-gratification that pervade Madonna's work.

Others worry that the teen and preteen girls who constitute the bulk of her audience are going to misread Madonna's signals. Calling her the "sultry burlesque queen of pop" avoids the truth that Madonna is just playing the same game as the boys. And playing it better, particularly when you sense how much of her act is a sendup of male stereotypes.

Sure, Madonna flirts, but she's more of a good-natured tease than shameless exhibitionists like Vanity and Apollonia. In "Susan," what you see is Madonna's famous bellybutton and vast expanses of soft white midriff. Nothing else. She wears no more makeup than Duran Duran or Prince, and her fashion sense is grounded in inspiration and available materials.

With her cherry-red lips, porcelain skin and semibleached hair, she's a curious fashion idol. Madonna is not a drop-dead beauty -- certainly more Rubenesque than Playmatish -- but her charisma is as obvious as it is constant, vacillating between come-hither invitation and go-to-hell exhortation. She smolders so openly that anyone getting burned never learned the adage about hot stoves, but she hardly seems ruthless.

Ambition. It seems to be a negative characteristic when attributed to women in America, but it has been the defining force in Madonna's career, informing her every move, from dance to music to video to film to the concert hall (she calls herself "a hyperactive adult"). She certainly did not emerge fully realized, and if one wants to look for the root of Madonna's relentless drive, it's most probably in her dreams of being a dancer.

Dance was a consuming passion in her Michigan adolescence. And while Madonna could find pleasure and release in the discos she frequented, she had to have learned in her ballet studies that personal sacrifices tend to be immediate, enduring and endemic to the world of dance, much more so than to the world of music. In ballet, there are no equivalents of self-produced albums and basement tapes, no room for accommodations.

A brief stint in an Alvin Ailey sub-troupe exposed her to other struggling artists just as driven as herself, but while some might have been frightened by the experience, Madonna apparently found it instructive and inspirational. From that point on she knew what she wanted, and what she'd have to do to get it. And she did it her way.

The pop culture hysteria that now surrounds Madonna will make it difficult for her to sustain such a spirited independence. She's still calling the shots, but larger forces are at work now. Take Madonna fashion, which has really been around for years, particularly in England and New York. Her fame allowed her to become the trash fashion plate that fed thousands of imaginations, and her lesson was self-invention standing against hedonist fantasy.

Now, for the lazy camp followers, there are several Madonna lines in the marketplace, while the thrift stores that fed the style in the first place have jumped their prices on such "Madonnish" items as lace gloves, black bras, rhinestone jewelry, crucifixes and see-through blouses. That so many girls are mimicking Madonna is a standard function of cultural stardom, a reflection of her, not on her.

"I always said I wanted to be famous," Madonna told Record Magazine. "I never said I wanted to be rich."

Looks like she's getting it both ways, not a bad fate for a Material Girl.