Juliette and The Licks, Barfly, London

Traditionally, actors trying their hand at rock music can expect a critical backlash. Ask Keanu Reeves. Ask Vincent Gallo. Cognisant of that, Juliette Lewis comes to rock with a manifesto, no less. "My intention is for our music to serve as an antidote to the self-doubt, apathy and fear that has become rampant in society", the 31-year-old, who was Oscar-nominated for her role in Cape Fear, has said.

While that statement may smack of overreach, on the evidence of their forthcoming mini-album Like a Bolt of Lightning, Lewis and her four-piece band certainly can rock. The work's title says it all, its short, sharp shocks tipping the hat to the likes of the MC5 and Iggy & The Stooges.

Done and dusted in 40 minutes, the band's live show follows suit. Lewis takes the stage in an electric-blue catsuit with red, strategically placed zips, announcing: "I'm gonna waste you, tease you, and then leave you." Vocally, she comes on like the combative daughter of Patti Smith and Iggy Pop, but it's the latter that has most influenced the way Lewis moves on stage: like Iggy, she strikes prize-fighter poses, or thrashes around as though wired to the same plug that powers her band's amplifiers.

"This next song's about..."

"Sexual frustration!" shouts a girl in the crowd.

"That's right, bitch," replies Lewis, then she and The Licks pile into the taut, rapid-fire groove of "Coming Around". Able, tattooed and toned though Lewis's bandmates are, they quickly become as invisible as that bloke in The Corrs. All eyes are on Lewis, who, as an actress, knows exactly how to magnify her focused, fully lived-in performance.

"American Boy" takes the puerile frat-boy mentality to task. Like a sharper, much more animated Courtney Love, Lewis is convincing as woman-to-be-wronged-at-your-peril. Hecklers are quickly steamrollered, and the music is too dirty and barbed not to be real. Lewis is not the only Hollywood actress on the circuit in recent months, but Minnie Driver coyly strumming an acoustic guitar this is not.

The cover of Van Halen's "Ain't Talkin' 'bout Love" is a welcome encore. Suddenly, as though to underscore further her debt to that veteran crowd-surfer Iggy Pop, Lewis launches herself into the Barfly audience, her head-first, horizontal posture, electric-blue attire and red leather boots making her look like rock's in-flight answer to Supergirl.

As a conveyor-belt of eager hands passes her overhead, Lewis fixes her determined gaze upon the back of the room. A hefty security guard is monitoring her progress, and as she reaches her target destination, the crowd roars its approval. When the lights come up, the two beaming twentysomething lads in front of me are already reminiscing about what has been a decidedly hands-on gig.