It’s funny how time changes things.

For example, when Joan Jett first clawed her way into the spotlight as the sneering singer-guitarist in teenage leather queens the Runaways, the idea of a gigantic, corporate-sponsored music festival proudly flying the punk banner would have seemed as utterly ludicrous as five girls playing hard-as-bricks rock ’n’ roll. First of all, there simply weren’t enough bands in 1976 to fill out that kind of lineup. And who would have gone, anyway? A bunch of junkies and anarchistic street trash? What company would want their name associated with a gathering like that?

Now, 30 years later, Jett is headlining just such a festival: the 12th annual Vans Warped Tour, the most durable package tour of the summer. And she’s still playing rock ’n’ roll you can build a house out of.

“I feel like I fit in, but I don’t analyze it,” she says somewhat tenuously, over the phone during one of the tour’s rare days off. It seems slightly absurd that she would talk so sheepishly about her position on the tour. Why wouldn’t she fit in? After all, this is a culture she helped give birth to. Her credentials are impeccable: She produced the first Germs album; she hung out with the Ramones; she taught Sid Vicious how to dress. Most significantly, she stomped out the gender lines etched into the history of pop. In rock, women of consequence had always been either delicate songbirds or bluesy belters. Jett, however, was something else: A female musician with, ahem, balls. She could shout, spit and bring down the hammer of the gods as hard as any guy could, and she would do so as if it were no big deal. If punk was an egalitarian revolution, then Jett was surely an important figure. So shouldn’t she be able to storm into an event that’s often referred to as “punk rock summer camp” and immediately feel at home? Not only feel like she’s at home, but like she built the friggin’ place with her own bare hands? “I don’t feel that so much, the influence. I go there as a music fan. I don’t really think about my place in it too much.”

Kenny Laguna, Jett’s longtime manager and songwriting partner, puts it a little more immodestly: “This is where she belongs — she’s one of the Elvis Presleys of punk rock.”

As true as that statement may be, Jett does have reason to feel like something of an outsider on this tour. At 48, she is old enough to be an average Warped-goer’s mother (even though she still looks like she could be drinking beer in the parking lot with them). And, let’s face it, she is not the most in-vogue artist at the moment. In fact, prior to the recently released Sinner, the last time she put out an album of new material the Warped Tour was crossing the country for the first time; that was 12 years ago. Even though her biggest hit, a cover of the Arrows’ “I Love Rock ’n’ Roll,” is one of those immortal songs everybody on the planet subconsciously knows, the audiences she is performing for this summer are so young they may be more familiar with Britney Spears’ rendition.

Moreover, the word “punk” has quite a different connotation behind it now compared to when Jett was getting started all those decades ago. She comes from a time when being associated with punk was a liability: When she initially embarked on a solo career in the ’80s, no label wanted anything to do with her (which led her and Laguna to form the still-existing Blackheart Records). These days, it’s a marketing tool used by record companies, fashion designers and — to be completely honest — Warped Tour founder Kevin Lyman to appeal to the kind of kids who hang out at shopping malls and watch MTV yet still feel detached from mainstream society. Stylistically, the definition has been stretched to such a degree that Jett’s version — rough-edged, guitar-heavy and speckled with elements of glam and classic rock — is almost archaic.

Thus far, however, she seems to be getting along just fine.

“The camaraderie is amazing,” she gushes, saying she sometimes borrows BMX bikes from Warped vets NOFX and cruises from stage to stage, checking out other bands and speaking to fans. As for the crowd response, well, she hasn’t been met with many blank stares yet. Those who’ve come to see her — a mixed bag of aging punks and worshipful newbies — have found a woman pushing 50 annihilating a bill made up of groups whose members are half her age and most of whom are dudes who probably consider themselves to be pretty kick-ass.

As when she began, Jett is again in a boys club, having to prove her worth. Ap-parently, time can’t change everything.

“There’s an illusion that everybody’s equal, but I can count the number of girls who’ve gone past the club level on one hand,” she says. “The glass ceiling still exists. A lot of people ask me why that’s the case, and I don’t have a good answer. It’s not the kids, it’s not the audiences, it’s not even the writers who have a problem. It’s some place in that establishment. … So I don’t feel I’m that establishment person. If anything, I feel even more outside of it today.”