For a band like Jane's Addiction, the thrill of headlining an outdoor festival varies little from the sparks set off by any kind of performance.

"I'm just the soundtrack to all the scenarios going on in the audience," said Stephen Perkins, drummer for the longstanding Los Angeles punk/metal/post-grunge/what-have-you band since its inception in 1985. Jane's Addiction will headline Friday night's lineup of the Bunbury Music Festival in Cincinnati.

"Whether you have 10 people or 10,000, you've got folks flirting and fighting, making up and breaking up. I really dig these big festivals where the audiences are there for the whole day. They're there to enjoy the bands they love, the bands they never heard of, the bands their parents told them about, whatever it might be."

But as conversation unfolds around tales from Jane's Addiction's early L.A. days to reflections on its recent album The Great Escape Artist, the real thrill of the modern-day rock festival is revealed: competition. The more bands on the bill, the bigger the contest.

"As a musician, I've always had that competitive spirit," Perkins said. "I had it when I joined my high school band. I even had it at bar mitzvahs, where there were other drummers around. That spirit just makes you play better.

"Say we're playing a show at a theater. If a band opens up, we're going to play great. But if you're playing a show with 25 other great bands and 10 other great drummers that are on the side of the stage watching you after all these other great shows have been going on all afternoon, you bring it a little differently. I think that level of competitive spirit makes the show better for the audience and a whole lot more fun for the musicians.

"We're all coming out of the same rock 'n' roll factory. But who is the Porsche, who is the Ferrari and who is the VW?"

Then again, Jane's Addiction — especially frontman Perry Farrell — helped redefine the contemporary design of the music festival more than 20 years ago. When the nucleus of the band — Farrell, Jenkins and guitarist Dave Navarro — broke up for the first time in 1991 — they have regrouped and disbanded twice since then — they used their farewell tour as a launch pad for an alternative-music festival called Lollapalooza. After a run as a touring enterprise, Lollapalooza became a stationary, weekend-long festival every year in Chicago.

"Lollapalooza in '91 was just seven bands on one stage on one afternoon," Jenkins said. "Now, you've got a weekend of 100 bands and four stages. There's a lot to pull from.

"Whether it's the backstage hang or the onstage hang, the vibe is always that we're here to show the audience a good time."