Ashlee Simpson has become fascinating for all the wrong reasons. It's not her abilities as a putative singer and songwriter that invite our attention. It's not the goth-lite grooming she's adopted as career contrast with her fair-haired singing sister, Jessica.

No, what stands out is the apparent sense of delusion that Simpson nurses about her work and its prefab origins. Raised by an enterprising stage dad who negotiated MTV reality shows for both daughters, Simpson seems not to realize just how concocted her persona is. In her mind, she's as real as any of the rebel rock chicks she's impersonating. If only as a case of life inside a show-biz bubble, Simpson compels further study.Simpson, 20, came to 3,000-seat Pompano Beach Amphitheatre on Saturday night for a sold-out performance. Touring in support of Autobiography, her hit debut, the star of MTV's The Ashlee Simpson Show also arrived vowing to actually sing. She had been caught lip-synching last fall on Saturday Night Live in one of those rare moments of true reality, when the packaging unravels.

Simpson had much to say on Saturday about that incident and its aftermath (which included her being booed at the Orange Bowl halftime show). None of it reflected a sense of atonement for having, in effect, lied to a national television audience. She mentioned "all of the critics being, like, super-mean to me," and said opinions don't matter so long as she and her fans -- mostly young and female -- hang together.

"We all have situations we deal with where you're like at school or whatever and you forgot to wear your pants," she said in a reflective aside. "That's what I felt like happened to me."

Pants in place, Simpson sang for more than an hour with backing from a five-piece band. Her voice, undoctored, was neither dreadful nor remarkable -- just a middling rock instrument with intonation issues and a bit of Joan Jett snarl. Simpson could front a decent cover band, and in fact appeared most at ease with a medley of '80s hits: The Pretenders' Brass In Pocket, Blondie's Call Me and Madonna's Burning Up.

The Autobiography songs mostly traded in lousy ex-boyfriends and contained a few well-turned rock hooks borrowed from the likes of Weezer and the Beatles. Simpson also excerpted Courtney Love's Celebrity Skin: "Oh, make me over/I'm all I wanna be."

Was that irony poking through the denial and self-pity? Sadly not. The Los Angeles resident went on to introduce a song about Hollywood by denouncing people there as "fake." She called Shadow -- as in stepping out of big sister's -- a song about "finding your own identity."

If identity consists of choosing a hair color and an audience, then Simpson has indeed found herself. She's secure in a place where super-mean people can't go and it's safe to believe her own hype.