How does a nice Rockville Centre girl like Halley DeVestern make us believe that she's got the brains, teeth and smell of an animal? That she's got a "bloody screaming jones" and "digs a moonlit howl?"

First off, it's her voice. Weaned on the Janis Joplin records of her older siblings, DeVestern's got pipes that aren't quite as seasoned as her inspiration, but they do show a sinewy mettle akin to Joan Osborne's or Maria McKee's. And on her self-released debut album, "Sugar Free," her incisive songs about emotions run amok ("I'll Light Myself On Fire"), bogus relationships ("Tied") and dysfunctional relations ("The Family Way") show that she's learned from masters such as Patti Smith and John Hiatt how to turn a phrase.

DeVestern says her arresting vision is just the result of "having these demons inside me which are demanding to get out and make some noise." In that case, when she takes the stage at this Saturday's WBAB Blues and Brews Festival, the Brookhaven Amphitheater will be in need of an exorcism. If you can't catch that show, she'll be opening for Joan Jett at the Bridgeview Yacht Club in Island Park on July 12.

Though she still spends time at her parents' Rockville Centre home, DeVestern lives in Park Slope, Brooklyn. For the moment, she's pulled back on her acting career (perhaps you recognized her as an Alex Kelly rape victim on "America's Most Wanted"?) to get her ya-yas out behind the mic. Word is quickly spreading about her prowess, and in addition to increasing radio airplay, she's just nabbed a nomination as best national act in the Los Angeles Music Awards.

A previous day job at a music publishing company motivated her to get serious about songwriting. When she saw people making money with lame songs, she figured she could do better. And she was tired of reciting other people's words on stage and screen.

"When you just talk and rant, people think you're crazy, but when you sing about weird stuff, people go 'Wow,'" DeVestern says of her emotionally raw songwriting approach. "If it sounds angry to go to the extremes of thought, then that's what I do. I just go to the extremes of emotions and feeling."