"What is that?" a woman asks, pointing to my wristband.

She has a wristband that looks similar. Almost everybody on this El car does. The subway is headed south, to Chicago's Grant Park, for the final day of Lollapalooza. We're all smooshed together like prisoners of war on our way to a death camp. The girl who notices my wristband -- I'd guess her age at maybe 19, 20 tops -- doesn't understand why mine reads "Artist Guest." Does it mean what she thinks it means? Am I a friend of an artist playing at Lollapalooza?

I'm hesitant to provide details. It'd be a different thing if I could say I was a guest of the National or the Postal Service or even Vampire Weekend. They're at least not 25 years my junior. I mutter the band's name under my breathe, half-hoping she won't recognize them.

"Holy shit," she screams. "You know the Blisters?!"

"Well," I backtrack. "I wouldn't say I know them, but..."

"Are you going backstage? Can you take me? Oh my god, oh my god, this is surreal."

It's surreal for me too, but for very different reasons. I don't get a lot of 20 year-old girls fawning over me these days. (Actually, I didn't get many 20 year old girls fawning over me when I was 20, but that's another story.) If she thinks my having connections with a band composed entirely of teenagers is impressive, well, I'm just getting warmed up.

"Funny story," I tell her with a smirk. "I'm pretty sure this wristband was supposed to go to the drummer's dad."

The 20 year-old just stares at me.

"Jeff Tweedy?" I ask.

"I don't know who that is," she says blankly.

Well then I guess she won't enjoy my story about picking up the wristband, which was left for me at the Tweedy household in Chicago. Sue Miller Tweedy, the family matriarch and co-founder of the late, great Lounge Ax nightclub, had emailed me earlier that day with specifics on where to find the coveted pass. "I'll leave it in the white cabinet thingie in the vestibule thingie under the frisbee," she wrote. It was exactly where she said it'd be, and then I'm standing there, in the House of Wilco, and I know Jeff's on tour with Bob Dylan, and Sue is with her kids at Lollapalooza. Things could have gotten real weird real fast. They didn't, of course. But the temptation was there. How often do you find yourself alone in the foyer of one of your musical idols?

"He's in a band called Wilco," I tell the 20 year-old.

"Oh yeah," she says. "My dad listens to them."

I tell this story later to Sue, who thinks it's hilarious (the part about the 20 year-old, not the part where I wondered if I should walk into her house and try on Jeff's clothes), and then tell it again to the Blisters, just moments after meeting them backstage. (Lollapalooza Backstage is actually just a big grass field filled with Airstream campers.) The guys in the band -- lead singer Henry Mosher (age 18), guitarist Hayden Holbert (18), bassist Tory P-Lopez (19) and drummer Spencer Tweedy (17) -- seem genuinely pleased that an older woman they've never met thinks they're worth squealing about in a subway.

"How was your poop?" I ask Spencer.

He doesn't flinch. "Fantastic," he says. "Much needed."

Our interview was delayed because, as Sue explained, "They're crabby because they need to poop." They went to poop in an area where I didn't have credentials to follow, so I was upgraded to a full-on "Artist" wristband, allowing me back into Lollapalooza's inner sanctum, where indie rockers can poop away from public leering. The pooping incident, and the Blisters' willingness to discuss it openly, just makes me like them more. I wish all the "stars" I've interviewed were this honest. Just once I want to get a call from a publicist, saying "Can we push back your phoner with Kid Rock by a half hour? He's in the middle of some grade-A pooping."

We stand in a circle on the grass and I experience the mortifying awkwardness of being a middle-aged man trying to initiate conversation with cool teenagers. I compliment them on their first record, Finally Bored (which you can and should buy here), particularly for the song "The Police," which contains the hummable chorus "What do you expect when you fuck with the police?" We talk about Lollapalooza, and what they're learned from their three years playing the festival -- their first time was 2006, when their oldest member was 12 -- and how they finally figured out that that smell isn't incense. We talk about their recent East Coast tour, which included a stop in Brooklyn, where Henry bought a pair of bright orange shoes at a thrift store "because it's Brooklyn and everybody has orange shoes," which were later eaten by an animal on a camping trip. And we discuss the sad elephant in the room, how this will likely be the last Blisters gig for awhile, since both Hayden and Henry are going to college in the fall. If they have any concerns that the band won't survive an extended hiatus, they're not sharing it.

"We'll be fine," Hayden says. "College is a path that we're all going to take, and we'll make the Blisters work around that."

"But what about the opportunities you'll miss?" I ask, playing the doom card. "What if Lollapalooza wants to book you for a a non-kid stage next year, and you're too distracted with college?"

"Oh, we'll be ready," Spencer jokes. "We're already negotiating for next year. We've been walking around the festival, karate-chopping headliners in their Adam's apples. You gotta let them know you're out there and taking over."

It's not a conscious choice, but I keep aiming questions towards Spencer. The obvious reason is that I like his dad's music quite a bit. But that's not a reason to favor him. It's not like if I impress Spencer, he'll tell his dad about me, and I'll end up playing cowbell on the next Wilco album. No, I keep gravitating towards Spencer because he keeps delivering consistently funny quotes. I remark on the band's apparent lack of physical fitness -- their non-Henry-Rollins-ness, if you will. Their lack of a gun show -- and Spencer responds with "Are you kidding me? Look at Hayden. He's a freakin' mountain man! He's a farmer! And Tory worked in a batting cage. And I'm a sportsman! I'm an athlete!"

The other reason I'm talking more to Spencer than the others is because we have a history. I interviewed him back in 2003, during the Blisters' genesis, when Spencer was just 8 years old. The band was preparing for their very first show, as a featured act in the "Letters to Santa" benefit at the Second City, a bill that also included Billy Corgan, Robbie Fulks, Steve Albini, and Spencer's dad. Interviewing Spencer was, at the time, the single greatest thing I'd done as a journalist. He was funny, intentionally and otherwise, and provided more slam-duck quotes than I typically get from adult musicians.

Here's an except from my story, which was published by The Believer in 2004:

"In the weeks leading up to their debut, Spencer and the boys blanketed their school with flyers. 'On the top, it said The Blisters in really big 3-D handwriting,' Spencer explains. 'Then there was a drawing of an explosion, and then the time we’d be playing. My mom told us that the time might change, so we went around to all the flyers and wrote ‘ish’ after the hour.'

"The big night finally arrives, and around 6-ish, the Blisters perform a stripped-down version of 'Heavy Metal Drummer.' The crowd literally gasps with joy. When Henry belts out, 'I miss the innocence I’ve known, playing KISS covers, beautiful and stoned,' it manages to be both ironic and sincere, adorable and genuinely cool. The crowd helps out, providing the 'woo-hooooo' during the chorus. Even Billy Corgan is smiling, and Billy Corgan does not smile."

A lot has changed in the last ten-ish years. Members have left. (Spencer's younger brother Sammy, who played bongos in that first Blisters show, asked to be fired. Since then, he's devoted his artistic career to interpretative dance.) And new members have joined. They've also stopped doing exclusively covers and started writing originals. And the school performances and benefits have been replaced with shows in adult clubs, at adult hours. This past June, they played a gig at Pete's Candy Store (which is not a candy store) in Brooklyn, and the stage lights went up at 11pm.

After the interview's over and the other Blisters wander away, Spencer and I keep talking. He admits that a giddily sinister tweet on the band's official Twitter account— "We're playing Lollapalooza on the KIDS STAGE! Knock over some children and watch our sets" — was his doing. "I'm not saying you should," he says of his violent suggestion. "But maybe you should."

And then he tells me about twerking, which is something he's seen 13 year-old girls do during Blisters' shows. "When we were in 7th grade, we'd get pissed off when the teachers tried to tone down the way girls danced," he says. "But now we play shows at these schools and it's like, what are they doing? Oh my god, that's the most horrible thing I've ever seen. Do I need to stop rocking and call your parents?"

A few hours later, I'm at Kidapalooza. It's exactly like what you're probably imagining. There are booths peddling things like "Tattooz" and "Punk Hairdooz" and "Yoga." There's a hip-hop workshop, where white kids can learn how to rap from African-American adults. (I watch a five year-old named Will rap the following verse: "My name is Big Will/ And I'm about to get ill.") I'm not on the Kidapalozza grounds five minutes before somebody yells "We need a medic!" A professional tumbler, performing between music acts, has broken his leg, and according to one witness, there's "a lot of goddamn blood!" As cops storm towards the accident, they weave around a 2 year-old with a pink fohawk, who's pounding on the cement with a plastic microphone and shouting "Rock, rock, rock!"

Top that, adult Lollapalooza.

The Blisters take to the stage at 4pm-ish, to a crowd of about 200 fans, a mix of tattooed adults and bored-looking kids. As they roar through their first song, a plane pulling a banner flies a little too close to the stage. The ad is for Trojan condoms, with the wincingly-inappropriate message "Can't Wait To Get It On!"

The Blisters' second song is "The Police," which I like to think they're playing because I begged them to. (Probably not, though.) Sadly, Henry opts against dropping the f-bomb and instead sings "Mess with the police." He does, however, still sing the lyrics "For every baby crying/ There's a dying amputee," so hopefully a few young minds are corrupted anyway.

Near the end of their set, Henry mentions to the crowd that this is their final gig before losing two members to college. "But we'll be back," he says, "to hopefully make more music." At least to my ears, it doesn't sound especially convincing. Maybe it's because he's in rock star mode and trying to seem coolly indifferent. Or maybe he knows that his band is going into the "long distance" part of their relationship, which is when relationships usually die.

I've been to college. It was a long time ago, but I remember it. College changes you. It's a new world, and for most of us, it's a chance to start fresh. You make new friends, date new people, reinvent yourself. Even the "good" kids from high school will take a hit off the proverbial gigantic bong with wizard stickers on the side. (Sometimes that gigantic bong is literal.) It's just what happens. You might even meet a bassist with a mustache and a Misfits t-shirt who's like "You wanna come over and jam sometime?"

The Blisters' second-to-last song at Lollapalooza is a cover of "The Weight." It's pretty amazing. And for some of us -- I can't speak for the entire audience -- it's hard not to think, 'Didn't Jeff Tweedy sing this exact song last night in Irvine, California with Bob Dylan and that guy from My Morning Jacket?' If you've been following the Americanarama Festival Of Music or have access to YouTube, you'll see that I'm right. Which is either some mind-blowing synchronicity, or somebody in the Blisters also has access to YouTube.

All four Blisters take turns singing lead. Spencer does the verse about Crazy Chester's dog, and it's pretty fucking awesome. His voice is confident. And eerily familiar. Close your eyes and that could be a young Jeff Tweedy up there. The song ends and a woman with a neck tattoo sitting in front of me turns to her friend and says, "Jesus Christ, I just had a Julian Lennon moment."

This may very well have been the Blisters' Last Waltz, but hearing Spencer sing with the authority of somebody who's spent the day drinking whiskey and smoking cigarettes (which, to the best of my knowledge, he didn't), you know it's all going to work out somehow. The Blisters may be back to "hopefully make more music," as Henry optimistically predicted. Or it may be the thing that Spencer Tweedy did before he went on to do the thing that everybody knows him for in another ten years.