You've heard the legend of rocker Joan Jett. It's partly the iconic tale told in the recent film The Runaways, with Twilight star Kristen Stewart in the role of Jett, of how she cofounded the '70s all-girl teenage glam-punk sensations. It's partly the episode of her solo career exploding in the '80s with the all-time sing-along stadium mega-hit "I Love Rock 'n' Roll." It's partly the story of her influence on and collaboration with '90s riot grrrls like Bikini Kill. Ultimately, it's the news of her return to the spotlight—a new book and greatest hits disc are out—and securing her stature as a pioneering role model for tough women in rock.

That's the familiar narrative of Jett the media star, but a deeper layer behind the storyline reveals a passionate rocker. Joan Marie Larkin has always been one of the form's purest true believers, a performer obsessed with sharing rousing music with her fans, a real-deal champion of the power of the music itself. She's one of rock's last great classicists, dedicated to golden-age music forms and ideals of rock community that have dwindled since the splintering of all things post-punk.

You can hear this commitment on cover songs across her catalogue, from crunched-up, good-time swinging oldies like Gary U.S. Bonds' "New Orleans" to more bracing statement-of-purpose oldies like Leslie Gore's "You Don't Own Me." She declares faith on originals like "Good Music," her recording of which features the Beach Boys and Darlene Love. Dedication is also the furious bleeding heart of Evil Stig, her one-off disc with Seattle band the Gits in the wake of the murder of their lead singer Mia Zapata. Jett's recent single, "Change the World," may be a simple set of well-intentioned clichés atop upbeat pop-punk, but in an era of skepticism, it's saintly that she still embraces her mission.

Joan Jett and the Blackhearts keep the faith this Friday, June 25, at the Sonoma-Marin Fair. 175 Fairgrounds Drive, Petaluma. 8pm. Free with $10–$15 fair admission. 707.283.3247.

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