A teen couldn’t find her mom’s 30-year-old demo tape. The internet stepped in.

The long-lost demo tape had always held a certain mythos in Charlotte Astor’s imagination.

For years, the Cherry Hill teen had heard stories about it, recorded about 30 years ago by her mother’s very loud, very short-lived, teenage hardcore band, Seed.

Shannon Astor, now 47, had been a vocalist for the group, just 14 or 15 years old, at a time when female representation within the genre was rare. Within a year or so, the group had disbanded — but before it did, the group, which typically practiced in a member’s parents’ basement, recorded a single demo. There had been only a few dozen copies produced back then, and they had all sold, scattering out around the South Jersey area.

For Charlotte, the tape became a kind of white whale — a relic of her mother’s hard-charging past, something the teen occasionally scoured the web for, to no avail.

She’d never heard her mother’s band. And she wanted to. Badly.

“Ninety-five percent of what I have about my mother is in the stories she tells me,” says Charlotte, 16, a junior at Cherry Hill High School East.

But a demo was something tangible. Something concrete.

“A demo,” she decided, “I can find.”

And so one night last spring, that’s what she set out to do.

She had little to go on: A rough estimate of when the demo would have been released (1993-94), a general geographic location (South Jersey), and a single lyric (“In the wind of the AM shadows cling to nearby trees as season shifts to satisfy the light from above”).

“I have been looking for this tape for 4 years,” she wrote in an appeal to her 1,000 or so Instagram followers, “... and it would mean the absolute world to me to find this tape.”

But something about her search — this desire to connect with a parent, to bridge a gap three decades wide — resonated. It became, within the tight-knit confines of the hardcore music scene, a united pursuit.

At an age when most teenagers couldn’t get far enough away from their parents, here was one launching a quixotic quest to better understand hers.

Soon, strangers from across the country were digging through old boxes in basements, or tagging old running buddies from Jersey’s 1990s hardcore scene in social media posts. Some reached out to old producers from the area, wondering whether the demo might have made its way into some dusty studio corner.

Messages poured in, too — hundreds of them — with suggestions ranging from the plausible to the outlandish. Had she tried getting in touch with Bruce Springsteen’s people? You never know what the Boss might have stowed away in some mansion closet.

“I suddenly had communication with so many people who I thought I would never in my life have any connection with,” Charlotte said. “California to Jersey, and everything in between.”

The lead singer of a well-known Jersey straight-edge band of the era, Mouthpiece, joined the search, messaging Charlotte after others reached out to him about the tape. (He vaguely remembered her mother, Shannon, but not the band.)

Much of the outside help, Charlotte notes, has come from the hardcore community.

Indeed, much of Charlotte’s young life is rooted in the same hardcore music scene that her mother’s once was. Like Shannon before her, Charlotte spends many nights at hardcore shows around the area, photographing the scene for the magazine she self-publishes, “Through Our Eyes.” And like her mother previously, she’s a member of the “straight-edge” hardcore community, a group with a shared collection of ideals that includes abstaining from drinking or drugs. (Her first flirtation with teenage rebellion came when she snuck out of the house one night to go to her favorite record store.)

And though her mother does not necessarily share Charlotte’s zeal for locating the old tape — “I’m not waiting for some garage band demo to be unearthed,” Shannon joked — she understands what it would mean to her daughter to have it.

“It’s special to me only because of how much she needed to hear it,” said Shannon. “I’m just so pro-Charli and everything that she does … But this is her journey, and something that was intrinsically important to her.”

To those in the scene, meanwhile, the response has been very hardcore.

“A bunch of people banding together to help this random girl find her mom’s thing,” said Quinn Brady, 19, of New York, and a friend of Charlotte’s. “Most people assume that hardcore people are not very nice or friendly. [But] there’s this inherent kinship. It connects people across the nation in a way that not a lot of other genres of music do.”

Those outside the hardcore scene have been no less enthralled, however.

In December, after NJ.com picked up the story, further extending its reach, a documentary filmmaker reached out about the possibility of doing a film on her quest.

Last year, after posting in some “old-head” hardcore Facebook groups about the tape, Shane Reynolds — a member of the Philly-based hardcore band God Instinct — stumbled upon what appeared to be the most promising lead yet.

“I found the guy who allegedly made the demo,” Reynolds said.

But when she got the man on the phone, Reynolds says, it proved to be a dead end.

The closest Charlotte came was last year, not long after she first posted about the demo on Instagram. Her mom’s former bandmate in Seed, convinced he must have kept something from that period, recovered from storage an old cassette that featured a recording of a single Seed practice session.

Charlotte took it home, pushed it into the stereo in her bedroom. She stared at the ceiling as the tape began to play and 30 years fell away.

For the first time, she could put a sound to the stories she grew up hearing.

“The first thing I heard was a few seconds of my mom talking,” Charlotte said. “That’s my mom, when she was 16. I’m listening to a clip of my mother, listening to her at the same age I am.”

Still, that small taste has only reinforced her devotion to unearthing the actual demo.

Charlotte remains realistic about her odds of finding it. No, it’s not likely to be found in some radio station’s studio. And no, Bruce Springsteen is almost certainly not in possession of a three-decades old demo tape from her mother’s teenage years.

But some graying hardcore fan from the ’90s, with a penchant for hoarding and a cluttered garage?

Stranger things have happened.

“I have confidence — unwavering confidence — that someone has it,” Charlotte says. “And that I will get my hands on it.”