Getting your Trinity Audio player ready...

Four years ago, the only ones who could tell them apart were, possibly, their parents.

Britney Spears, Christina Aguilera, Mandy Moore and Jessica Simpson looked alike, sounded alike and even “acted” alike–you know, each claiming that she was “different” from the other three.

At that point, whatever. Same hair color (blond), same music (fluffy, innocuous pop), same videos (looked like workout tapes).

Half a decade later, however, each has not only managed to stick around–a feat unto itself in pop music–but also to strike out in her own direction. Who’da thought?

Mandy Moore, 20

First words: On May 2, 2000, the Tribune ran excerpts of a conversation with Mandy, who had just been elected Favorite Rising Star at Nickelodeon’s 13th Annual Kids’ Choice Awards. Asked how she felt about comparisons to Britney, Mandy said: “It’s flattering to be compared to someone so successful. I just don’t like how people judge me before they see, hear or meet me. They see that I’m blond and sing pop music and assume I’m just another Britney. It’s certainly not bad to be another Britney, but I’m not–I’m Mandy. They forget that I’m only 16 with less life experience and therefore, sing about what I know and have experienced. I’m comfortable being 16 and don’t believe that in order to be classified as ‘sexy’ or ‘beautiful,’ you have to show lots of skin.”

Flashback: Mandy wasn’t even old enough to drive when her first record, the falsely named dance-pop disc “So Real,” came out. Hoping to capitalize on the Britney boom, her record company re-released it a year later and changed her image from innocent to not-so-innocent.

Road she took: Not only did Mandy change her hair color, she switched career paths, focusing on films (“A Walk To Remember,” “How To Deal”) rather than music. When it came time for her to do a new record, she freaked everybody out by putting out “Coverage,” an all-covers disc made up of rock/folk renditions of songs by Elton John, Carole King and Joni Mitchell.

Hair is she now? To avoid getting tagged a Britney clone, she cut her hair and painted it black.

Current project: Her latest movie “Saved!” is in theaters.

Significant other: Romance with tennis champ Andy Roddick ended in March.

Christina Aguilera, 23.

First words: On Jan. 14, 2000, a Tribune profile of Christina described her as appearing “blessed with a preternatural sense of self-possession common only among 18-year-olds who are used to causing riots in tiny Eastern European countries.”

Asked how she felt about being a superstar, Christina said: “It feels like I’ve been dreaming this forever and then it happens and it feels like a whirlwind. … It’s a lonely business. You have no sense of a home life. You’re constantly traveling, and you miss your friends.”

Flashback: Christina’s first single, “Genie in a Bottle,” was typical teen pop but huge, putting her in direct competition with onetime friend Spears. There still exists a McCartney/ Lennon conflict between the two, only the question isn’t talent as much as: “Who’s hotter?”

Road she took: Of the four, Christina’s the one who made a serious bid to be a singer. Yes, she has changed her look more times than Marilyn Manson, and with each image change, it seems, fewer and fewer clothes are involved. Underneath it all, a pretty decent voice is begging to get out.

Hair is she now? Black. Er, brown. Um, strawberry. Well, what day is it?

Current project: Recovering from vocal strain–she had to ax her Stripped tour.

Significant other: Jordan Bratman, a talent manager in the music industry.

Jessica Simpson, 23

First words: On Sept. 6, 2001, the Tribune previewed Jessica’s Dreamchaser tour. To prepare for the shows, Jessica lost 15 pounds and worked with a choreographer after record-company execs told her she’d be more successful if she were slimmer and learned to dance.

“I’m gonna do all that I can to be a better artist and a better performer and to get more fans, just because I know that it’s my calling to be a positive role model for a lot of people,” she said.

Flashback: Jessica had moderate success with her debut, “Sweet Kisses,” and “I Wanna Love You Forever.” Her biggest moment, perhaps, was opening for Ricky Martin at Madison Square Garden. Unfortunately, the show is memorable to her for another reason: She ripped her leather pants on stage. Right between her legs. And no, she was not wearing underwear. Thankfully, mom was handy with another pair of pants.

Road she took: Jessica was pretty much a wash until she appeared in another medium, television, first with a recurring role on “That ’70s Show” and then on “Newlyweds: Nick & Jessica,” her reality project with husband Nick Lachey. As a result of the show’s popularity, sales of her latest disc, “In This Skin,” have been boosted. If it were not for the show, she’d be done.

Hair is she now? The only one who has stayed blond. “Ditzy” and “brunet” just don’t go together as well.

Current project: Besides “Newlyweds,” Jessica is hawking edible body creams called Dessert Beauty. ABC recently rejected “Jessica,” her stab at a sitcom. But she is the front-runner to star in the big-screen version of “The Dukes of Hazzard” as, of course, Daisy Duke.

Significant other: Lachey of the boy band 98 Degrees.

Hottest of the bunch?

Jessica Simpson tops Star magazine’s list of the 12 hottest, richest women in Hollywood. Not bad for someone who can’t tell the difference between chicken and tuna. Simpson attributes her success to her open personality: “I just want to be who I am,” she told Star.

But don’t be fooled by her seemingly ditzy persona. Simpson is a savvy businesswoman. At 23, she has published a book (“Jessica Simpson I Do: Achieving Your Dream Wedding”), is close to snagging the role of Daisy Duke in the upcoming movie “Dukes of Hazzard” and pulled in $4 million last year, Star reports.

REDEYE

Britney Spears, 22

First words: On Jan. 31, 1999, Britney’s name appeared for the first time in the pages of the Tribune. In a short review of her debut album, “Baby One More Time,” she was described as “sweet, sassy and engagingly self-confident.”

On July 24, 2000, a story in the Tribune about Britney’s skimpy attire included this defense from the pop tart: “I only wear these crop tops because other clothes would make me sweat when I dance.” And about her dreams of a rise to the pop throne: “I want to become like Madonna, only without all the men gossip and scandals.”

Flashback: With the success of her debut, 1999’s “… One More Time,” Britney led the teen-pop revolution of the late ’90s. Wearing both high heels and sneakers, she preached the values of abstinence while at the same time sexily cavorting on MTV.

Road she took: Britney can barely sing. She has made up for it, though, becoming the most controversial female pop star since Madonna. Basically, she sells sex more than music. Just ask men’s magazine FHM, which this year voted her the world’s sexiest woman.

Hair is she now? Back in March, London’s Evening Standard reported that Britney had been spotted with brown hair, though recent photos showed her back to platinum blond.

Current project: With the summer leg of her Onyx Hotel tour canceled so that she can recover from knee surgery, Britney is spending her recuperation time with fiance Kevin Federline.

Significant other: Federline–their romance went public after a beach romp in California two months ago.