One thing you can say about Madonna: She's unpredictable.
On the verge of her 50th birthday, the "Queen of Pop" has had more incarnations than the Dalai Lama. And she shows no signs of settling into middle age either.
With "4 Minutes to Save the World," her first single from her new album, "Hard Candy," she earned her 37th hit to crack the Top 10, surpassing Elvis Presley, the previous record holder. And she's about to embark on what looks to be a sell-out tour.
If Madonna looks like she's sitting pretty, it's because she never sits still for very long.
"Very few people have the staying power that she has," said Bradley Jacobs, a senior editor at Us Weekly, where Madonna has recently graced the cover recently for her friendship with Yankees slugger Alex Rodriguez. "Look what's happened to Tom Cruise. He was on top and fell off. Nicole Kidman's not getting lot of work. Madonna refuses to go quietly."
"She comes up with new stuff. Every album she works with new people," Jacobs said. "She's aggressive with pursuing young people. That's how you stay current. You don't wear the same clothes. You keep people guessing and mystified. What new idea has Cher come up with? Michael Jackson started out at the same time, and they're like apples and oranges. Overall, Madonna has always succeeded by staying ahead of curve."
There's a reason why the media refer to Madonna as the Queen of Reinvention -- a title she dislikes but still co-opted for her 2004 tour.
"She would say a girl likes to change her hair color or hairstyle," said Keith Caulfield, an analyst at Billboard magazine. "She's just playing dress up and trying new things."
But each new look -- the sexpot, the spiritualist, the lady of the manor -- seems to precede a new album. Calculated? Or the result of her voracious interests?
"There are some artists who might be more perceptively stable in what their image or sound is," Caulfield said. "Springsteen has an identifiable sound and look. He's not going to come out suddenly with a mohawk. He's a different kind of artist."
"Madonna is a pop artist who has always been into different kinds of sounds," he said. "She's a voracious collector of art; she's a fan of music and film, not just mainstream fare. What's she's doing is not super cutting edge. She's usually hearing something she likes and taking ideas and putting them out there."
Looking back at some of Madonna's more memorable moments, it's clear she has had an influence on pop music, fashion and the zeitgeist.
She's No Virgin
When Madonna came out with her first album in 1983, with inflections of black music, she seemed to fit neither in the rock nor R&B categories. But it didn't take long before she was burning up the charts and making headlines, like the time she famously rolled around on the stage in a wedding dress singing "Like a Virgin" for the MTV Video Music Awards.
And little girls copied her rag-tag, bangled style after she appeared in the 1985 film "Desperately Seeking Susan."
"That's when I got hooked on Madonna," said Clare Parmenter, a 35-year-old British biomedical scientist who founded the fan site Madonnalicious.com in 2001. "I was just becoming a teenage girl. The sparkly boots, the hair tied up like that, I hadn't seen that. It was a look for a teenager to aspire to. It looked like you could go to a charity shop and get that look."