They had the black mesh T-shirts. They had the crucifix earrings. They had the armfuls of black bracelets and the tangles of beads and the carefully applied beauty marks and the tight knit skirts and the floppy bows holding back crimped hair.

Saturday night, at Madonna's sold-out concert at Merriweather Post Pavilion, row after row of just-about-pubescent girls pouted their little lips and sang "Material Girl" along with their idol. They swayed their 13-year-old hips, rolled down their knit skirts to reveal their 13-year-old-bellybuttons and tottered about on needle-thin heels.

One Madonna after another. Maybe the hair beneath the bow looked a bit cleaner than hers. Maybe there was less to reveal under their mesh shirts than under hers. Maybe they were indistinguishable from the 537 other girls wearing the same crucifix earrings, lace stockings, etc. Maybe their mothers were with them.

None of that mattered to the Madonna faithful. From their clothes to their comments, they followed the Madonna gospel gladly.

Madonna doctrine has several requirements beyond its sartorial demands.

There's the Law of Originality, as in, "I like her because she's so original."

"She's so original," said Lisa Perry, 15, of Parkville, Md., who was wrapped in red and black knit and lace.

"She does everything that's new," said Bernie DiPasquale, 17, of Rosedale, Md. "Everything -- like that!" he added, as Madonna launched into "Like a Virgin."

"She's totally unique," said Christy DiPasquale, 15.

And if her followers begin to look all rather similar, well, that's because the observer's vision is not acute enough to pick out the details.

"They're not all exactly the same," said Perry. "It's all how you put it together. The pearls, the lace."

There's the Ritual of Preparation. It's all topped off with a photograph of the Madonna adulator in full regalia, taken by the parent who also chauffeurs the fan to the concert.

"It took me four hours to get ready for this," said 14-year-old Julie Thompson of Annapolis.

Madonna-Julie and her friend, 15-year-old Madonna-Erin Dober, were in Basic Madonna. Between the two of them: six pairs of earrings, one green bra with straps showing, two see-through lace T-shirts, eyebrow-pencil beauty marks, strand after strand of rhinestones and pearls and two knit skirts that fit like Saran Wrap.

"I had to tease my hair and my mom made some of my clothes," said Thompson. "But it's worth it. She's such a good singer."

"Yeah, she expresses herself really well," said Dober.

"Our parents don't like us to act like her," said Thompson. "But . . ."

"She gets all the guys," said Dober.

There's the Societal Phenomenon Hypothesis.

"I love her. Madonna, she's so cool," said Amy Flexwell, 18. "She's like a great gifted personality. She's not just sexy. She's a personality. She's what she wants to be. I mean, she affects everybody. Look, everybody wears a lot of bracelets now."

And there's the Anti-Fad Philosophy, used to counter anyone suggesting Madonna is not forever.

"It feels like I was first to like her," said Lisa Cox, 15, from Hagerstown, Md., who wore matching black lace gloves and socks, "full-mesh, half-mesh" T-shirts, as she put it, and more.

"The only bad thing about it is she's so far away," she said. "I'm on the lawn. But just knowing you're in the same area . . . Before the concert, I thought that she was just getting worn out too fast, but then you come to a concert and it revives everything all over again. It's like they did with Michael Jackson -- all the buttons and T-shirts -- and now he's dead. I'd hate to see the day when she wasn't there."

Some, however, were determined to declare their independence.

"My name? Just call me Susan. Desperately Seeking Susan," said Susan Boren, 23, of Potomac, one more in a line of golden-curled Madonna look-alikes. Susan was watching all the other Susans dance to "Material Girl" but she was having nothing of it and stood completely still. "I was dressing like this before Madonna was . . . Am I trying to look like her? Nooo. This is natural. All Natural."

Not everyone at the concert was in mesh and lace. Much of the almost completely white, almost completely early-teen crowd opted for Bermuda shorts; yellow, pink and pale green shirts; white skirts. Even the Madonna clones were pretty clean-cut. Under each beauty mark was a well-scrubbed upper lip and most of the makeup had more to do with Maybelline than Madonna.

"She doesn't take things that come -- she grabs them," said Evan Corn, 17, of Potomac. "She's prevailing. I learned that word in English class."

"She doesn't really care what people think," said Cissi Wyatt, 13, of Springfield.

All of which is fine for Madonna, but for her fans? There wasn't much prevailing or grabbing going on among them. Standing in groups of four or five, clutching their posters, giggling, they watched the passing boys, but didn't approach them. Where one went, the others followed, and when it was all over there was a long, tired line of girls at the phone, calling their parents to tell them it was time to pick them up.

But to some, even the tame rebellion of the baby Madonnas was disturbing.

"We don't understand why all these people are trying to look like her," said Theresa Scalco, 21, who fell into the neatly-combed-hair-floral-print-pastel-color school of clothing.

"We think it's bad for all these little kids to admire her," said Kim Machak, 22, who was similarly attired. "Did you see her movie? She was a slut, she smoked."

"We like her music -- it's fantastic," said Scalco. "She's got a great voice."

"But her life style," said Machak. "As far as she portrays it -- we don't think it's good for little kids."

"A fad's okay," said Scalco.

"But we're talking about the marks on the face," said Machak.

"We saw a girl, she must have been 7, in lipstick, high heels," said Scalco.

"An earring bigger than I would wear," said Machak. "You look at them and wonder why they want to be someone else."

"Maybe people think I dress funny," said Scalco. "I wear big, baggy shorts. But I feel I'm my own person, not trying to be someone else." She paused and looked around. A tight black skirt and bundle of lace walked by.

"Perfect example!" Scalco said. "Nowadays, people are more interested in people looking at their clothes than in watching the concert."