When the bit of bottled summertime called "The Middle" made Mesa, Ariz., quartet Jimmy Eat World one of 2002's breakout success stories, some of the band's longtime fans couldn't help but feel an all-too-familiar pang. Another of the underground acts they'd embraced and nurtured was leaving the fold; a formerly ignorant wider audience had finally deigned to pay attention, and a bigger world beckoned.A little sappy-stupid, maybe, but they feel it just the same. Listeners who find their favorite bands through mainstream radio airplay won't ever understand what if feels like when a fan's favorite van-touring little D.I.Y. outfit — the group they felt only their close friends listened to, the group that knew their name from seeing them at shows so many times — blows up. It rules, and it sucks. You're happy for them, and you're sad for you. It's bittersweet.

But a look at Jimmy Eat World's history twists the plot, to reveal a band that's always had one foot in the underground scene, and one in populist, accessible rock music; a band that originally found a quasi-punk audience by being punk enough to not be punk, as it were. Jimmy Eat World never completely fit in anywhere, and their current dual citizenship fits them as well as any status would, or could.

"We just want as many people as possible to hear our music," says guitarist and sometime lead vocalist Tom Linton. "We don't really think about credibility, stuff like that, too much. We pretty much just do what we do."

By the time the foursome got together in 1994, preconceptions of the all-ages circuit as being completely punk-dominated were basically obsolete. It was and is a place for musicians who can't or don't want to attract the notice of what most people think of as "the music industry," and are willing to handle everything — from recording and pressing records and CDs to booking tours — themselves. This is where Jimmy Eat World found its earliest and most ardent fans, fans that stayed with the band as it quickly shed its more generic pop-punk influences, but not its way with infectious harmonies and hooks.

That usually fickle, indie-centric audience stayed with the band as it signed to major label Capitol Records, and released its second full-length Static Previals in '96. Though Jimmy Eat World enjoyed a major label's larger recording budget, Capitol was indecisive about how to market the group, so its fan base grew the way it had before the deal — organically, by word of mouth and underground. The band toured on a shoestring, and put out more EPs and compilation tracks on smaller imprints. From the members' perspective, being affiliated with a corporation that had considerable muscle to flex wasn't much different than doing it themselves, beyond the facts that the records sounded better and were available in more stores; that sense of operating under the radar continued through 1999's ambitious, evocative masterwork Clarity.

"There really wasn't too much attention paid to our band [by the label]," remembers Linton. "We had to do it ourselves, getting in the van and setting up our own shows, selling our own merch. We really didn't have any other choice, so that's how we did it.

"A lot of people think once a band signs to a major, they're instantly rich. But it's not true. Even now, we were in the airport a couple of weeks ago and some guy was telling us he thought we'd have our own private jet. That's just not how it goes."

Despite a steadily rising profile, Capitol dropped the band. Captiol's loss. The sort of dynamic, yearning, harmony-laden indie-pop perfected on Clarity exploded under the aegis of emo shortly afterward, and Jimmy Eat World was hailed as the unassuming forerunners of the genre. Meanwhile, the group itself never looked back, recording an unabashedly simple pop-rock album, without a deal, on the money it had earned from all those no-budget tours. Another big label, Dreamworks, released it.

DreamWorks' gain.

Jimmy Eat World, the album, spawned three hit singles, making Jimmy Eat World, the band, an overnight success eight years in the making.

"During that time, we went out with Green Day and Blink-182, and we were opening up, so it was hard to judge what was really going on with us," Linton says. "It's kind of weird, because we really didn't notice it too much … it was more like talking to our parents, family and friends back in the States, and they were telling us they saw the video, or heard our song on the radio."

Everybody saw their video. Everybody heard their song on the radio. And everybody became a Jimmy Eat World fan.

"That's a tough one," says Linton, when asked if the band ever thinks of fans in terms of "old" and "new."

"Yeah, I guess so. We see a lot of people that have been coming to our shows for a long time, and it's cool that they're still supporting us. But the new fans are just as important, and hopefully they'll support us for as long as the old fans have."

Two years later, it seems as if fans old and new are both still around. The newest album, Futures — a solid mix of Clarity's orchestrated melancholy and Jimmy Eat World's sweet, crunchy bursts — delivered a hit out of the gate in the revved-up single "Pain." And the band continues to exist simultaneously in two worlds, seemingly beholden to neither of them: they're playing MTV's annual New Year's Eve bash, but are currently touring venues much smaller than their success might warrant, in order to keep things as intimate as possible. Such juxtapositions have just become par for the course.

They're just doing what they do.

"The people who bought our last records, we're always hoping they'll be into the new stuff we're doing," says Linton of Futures, and the future in general. "But it's hard to tell what's going to happen, as far as what's going to be on the radio, what'll be the next hip thing.

"We don't really think about it too much."

scott.harrell@weeklyplanet.com