From Bowie in pre-Ziggy Garbo-garb to femme fatale John Cameron Mitchell and his angry-wigged inch, a rocking man in women’s wear is hardly new. Yet on Jimi Mooney -- or rather his femme alter ego, hardass gender-fuck Helen Back -- the rock girl demeanor looks and sounds brand-new, despite the old ripped-up fishnets.

But Mooney, 37, is no novice to Philly stages, having worked Big Mess Theater since its inception. And Helen is hardly a new creation; Mooney first became the black-wigged, mini-dressed Greta back in the '80s at Chip Dish's Club Voodoo and the late Lou Pratico's House of 3D Productions, which set up shop there.

Now, Back has taken Philly's alterna-scene -- in live performance and on a new DVD, Homo Faux Pas -- by storm with a strategy based not on drag-as-novelty, but rather a real rock ethos.

Not that the other way is bad. But Back -- sporting optical-illusory tops or sequined mini-dresses, clunky high heels and wide-open eyes -- is a genuine balls-out cabaret-rocking babe, a teetering crooner with stunning vocal power, be it wailing originals or belting out covers of T. Rex, the Dolls and Bowie's "Oh You Pretty Things" with a taut punkish band (The Str8 Razors) in an emotive carousel of a voice that would make Marc Almond weep. "I don't think what I'm doing is nostalgia; I'm just going back to when rock was powerful. If anything, to save songs from being used to sell cars or laundry soap. I would have run away from home if I heard that shit, the Dolls and T. Rex, back when I was a child," says Mooney. "I forgot how rock 'n' roll could give me a hard-on until I brought Helen back."

So why Helen and why now? "I know it sounds cliche, but 9/11," says Mooney, as to why he resurrected his alter-ego. "I had to do something with the anger and disillusionment I felt, where I could vent and have a good time." The once-insecure Mooney, more realist than nihilist, decided to "use the best parts of myself and stop being afraid of the power of my opinions and abilities."

Before Back, there was Mooney, a Northeast Philly Catholic kid who bought every Bowie record ("I loved Space Oddity; it was like this landscape of fantasy and solitude, something I knew a lot about"), worshiped Hammer horror movies and Dr. Shock, went to St. Joe's Prep and found "other closeted queers to befriend." He exploded into a glamorous creature upon moving downtown in 1982, when he discovered Siouxsie and arty-goth bands like Bauhaus and the Batcave stuff and played in bands where he copied Alien Sex Fiend and Suicide.

While discovering the image, glamour and mystique of new wave spots like East Side Club, this geeky kid was also checking out the world of gay bars. "Equus was the first place I went and it was like every nightmare I had that being gay was like. Back then places were mixed and gay men were cooler, so you could find a boyfriend for the night who liked Siouxsie and didn't scream when they saw your eyeliner."

It wasn't until 1989 when Mooney met Louis Pratico -- a.k.a. garish alterna-dragster Merzy Jones (and one of this reporter's very dearest friends) -- and Greg Giovanni, that Mooney got down to the business of making that eyeliner work for him as dramatic/comic/performance art persona. At late-night venues Voodoo and Revival, Pratico and Mooney donned trashy clothes and makeup, rethinking the old-school drag aesthetics of Bette Davis impersonations for house-heads and X-freaks. Mooney and Giovanni became friends while working at Duck Soup on 12th and Spruce. Together they did performance pieces at Killtime.

"I was totally hooked," says Mooney, who joined Giovanni's Big Mess theater workshop and his cabarets at Penguin Place. There they evolved legendary sagas like Napoleon Pullapart, The Bacchae, The Duchess Malfi, Taking Tiger Mountain Lip Sync Show, Medea of Springfield (aired on WHYY's Spotlight series) and The Ixiondae, as well as appearing on the Big Mess CD, A Little Trash Goes a Long Way, singing Brian Eno's "Third Uncle" and "Us and Them" by Pink Floyd. Like most of us, Mooney misses Giovanni's grand-scale theatricals, but understands that Giovanni, like Mooney, has his own row to hoe.

"Greg has been my biggest influence," says Mooney of the Philly theater institution. "He opened me up to the idea that you could completely create an illusion or an interpretation of reality and do it with nothing more than ambition. Louis, too -- to just have the balls to get your dream into reality. He was witty and could really hurt people sometimes, me included. I admire that. I'm too nice, sometimes -- let people walk all over me. I've toughened up a lot, doll."

Enter Helen. Though Mooney had sung on several projects, like the techy noise duo Mouth Pet that opened for the Indigo Girls at the Knitting Factory ("I sang my little queer songs, no structure -- what a nightmare"), the indie-rocking Bottom (who did "Catholic Boy" on Mike Viller's Jim Carroll tribute CD) and his own synth-poppy mp3s ("they loved me in Germany"), it took a glam version of "The Grinch Theme" at 2001's Big Mess Cabaret at the Troc to re-Helenize him. "Computer music felt like an illusion. Helen and I were in love again and in love with rock 'n' roll."

"Androgyny excites me," says Mooney, who, as he did during his 3D days, reinvented drag's tacky idealism to suit a distillation of his rock fantasies rather than heighten his womanhood. "It's in the moment, not a pretense. I want to reveal to the audience what these songs mean to me, how they make me feel, the drama, humor."

Beyond the kitsch and easy humor of a man in a dress, Mooney's made Helen a living, breathing entity, a blend of self and character that doesn't ever play with the illusion of female. "I stopped wearing tits years ago. Sometimes I don't even wear a wig. I am more into the content of what I'm doing, the songs, my own songs." Inspired by the current climate of terror, Mooney's songs seem knee-deep in social confusion. But it's the sound of vexed conviction, the hard punkish Str8 Razors, that gives Back an edge.

Guitarists Chris Unrath and John Doe, bassists Tracy Stanton and Andrew Chalfen and drummer Ned Sonstein do have other commitments in local bands. But as Helen says, "I don't think I'm taking them away from their other bands, but I'm addictive. I'm definitely the Œother woman.' You can't stay away for too long before you need a fix." I couldn't concur more, doll.

Helen Back and The Str8 Razors perform Sat., Dec. 7, 11 p.m., $5 (free with El Vez ticket stub), The Balcony, 1003 Arch St., 215-922-LIVE.