No Lip-Syncing: Ashlee Brings 'Chicago' to London

Sept. 25, 2006 — -- Not long ago, people doubted whether Ashlee Simpson could really sing.

Now, she says she can relate to her role as the fame-hungry Roxie Hart in the London run of "Chicago" as the musical nears its premiere.

"The play absolutely is all about celebrity and wanting to be famous and have your name in the papers and your picture in the papers," the 21-year-old pop star told reporters.

"And in that sense, it's been kind of cool because I've really got to connect to that 'cause I've seen that world and been in that world."

It took a little time for Jessica's less-famous younger sister to emerge from her shadow.

But Simpson has always shown some talent.

At 11, she was the youngest person ever admitted into the School of American Ballet, and three years later, she was dancing in Jessica's stage show.

But her career hit a snag with that infamous 2004 performance on NBC's "Saturday Night Live," when she was due to sing "Autobiography," and a pre-recorded track of "Pieces of Me" -- which she had performed earlier that evening -- began playing.

An embarrassed Simpson was left holding her microphone, dancing an awkward jig as a joke, and apologizing days later.

While many stars sing with the aid of backing tracks at live events, Simpson became a national joke.

But she's worked hard to overcome that, and she'll have no high-tech trickery to fall back on as she makes her debut at London's Cambridge Theatre in London's West End.

She's taking on the role that earned Renee Zellweger an Oscar nomination.

"Doing theater has been extremely humbling," Simpson said, "because it's not about who you are. You are not a celebrity when you come here. Everyone is equal. Everyone has to work together."

Ashlee on Jessica: 'We're There for Each Other'

Simpson decided to take the role shortly after R&B singer Usher announced that he was joining the Broadway production of "Chicago."

He debuted several weeks ago in the part of showbiz impresario Billy Flynn -- played by Richard Gere in the 2002 movie -- to lukewarm reviews and a spike in ticket sales.

Simpson would hardly deny the cutthroat competition in show business, and in that respect, she can relate to her Roxie character.

But one young star she isn't competing with is her sister, who will be in the audience when she takes the stage.

"There are people you can have a competitive streak with. But Jessica and I don't have that," Simpson said. "We've got to be there for each other."

"We can have other people that we're competitive with, but not each other."

Recently, the Simpson sisters came under attack from Texas evangelist the Rev. Bob Harrington, who told Australia's New Weekly magazine that Ashlee and Jessica had lost their Christian values.

He also predicted that "their breasts will sag and their faces will wither, and they will be left with nothing but a hollow shell."

While she and Jessica are famous for their club-hopping, Simpson tried not to take the attack too seriously.

"I just think that story is a bit crazy and you should watch what you say. … Don't curse something on us."

ABC News Radio contributed to this report.