In a typical May, Rainer Fronz is busy as hell coaxing money from sponsors, organizing merch and, in his words, finishing up “all that nonsense” needed to put Caterwaul together. The three-day Minneapolis “heavy, loud, abrasive music” festival, celebrating its fifth year this June, doesn’t just happen, you know.
This year, however, the 50-year-old Fronz is stuck in a Fairview cardiac ward, where he checked in about a month ago when his heart went on the fritz. (Again.) When he leaves, if all goes well, it’ll be with a different heart than the one he came in with. Neat.
This is where a more sensationalist writer would let the suspense build: What will happen to this longtime fixture of the Twin Cities music scene? Will the festival he built proceed as planned?
But I’m too classy to pretend there’s a super-dramatic tale to tell here. While any medical procedure carries risks, Fronz’s prognosis is good. He’s at the top of the waiting list. He’s even insured—though naturally, whether his insurer would cover the transplant was touch and go there for a while.
No, this is simply a look at how one underground lifer has made his mark on the local scene while enduring persistent health problems, with a tangential call to become an organ donor if you aren’t already. (You can sign up here.) As Fronz says, “When you’re dead, you don’t need that shit anymore, so recycle it.”
And yes, Caterwaul will continue, taking over Zhora Darling in northeast Minneapolis the first week of June. And though Fronz will be sitting it out, it’ll reflect the work he’s put in over the past decades as the founder of Learning Curve Records, one of the Twin Cities’ most significant 21st century labels, and just simply as a guy who makes cool stuff happen.
Here’s how Caterwaul co-founder Conan Neutron, the Milwaukee-based host of the podcast Protonic Reversal, puts it: “Rainer is an objective force for good and an advocate for beautiful freaks, nerds, and weirdos. He isn’t the loudest, he isn’t the most online, but he is consistent, he does the work, and he is never to be underestimated.”
And here’s how Fronz reflects on what has happened to him since founding Learning Curve: “Here I am, 23-odd years later, waiting for a heart transplant, putting out records, and likely streaming a music festival I helped book but am currently of no use to. Which is about as on-brand as it gets.”
The rock ‘n’ roll lifestyle isn’t what did Fronz’s heart in—unless you consider a lack of insurance part of that lifestyle, which 25 years ago it kinda was. Pre-Obamacare, what could be more punk rock than not being insured?
“In the early 2000s, I had pretty bad viral pneumonia, so my chest filled with fluid and my heart swelled up,” is how Fronz says it all started.
At the time he was just out of college at St. Olaf, where radio station KTSO had prompted his dedication to underground music. He interned at “the only place that would take me”—storied local label Amphetamine Reptile, where he was tutored in the label biz by AmRep founder Tom Hazelmeyer. After a stint in Portland, Oregon, a town he found very similar to the Twin Cities, Fronz returned, bouncing around the punky Grumpy’s/AmRep orbit without quite finding a niche.
He made a decision. “If I couldn’t get a job in music, or work at a label that was putting out music I cared about, I might as well do it myself,” he says.
“I asked Paul and Jeff from Vaz and Nick Sakes from Sicbay if they wanted to do a split 7-inch. Then I asked Chris Mars if I could use some artwork, and LCR001 was born.”
That initial success convinced Fronz he was on to something. “That record was a breeze. A banger,” he says. “I thought, ‘Well, shit, I’ve got this label thing in the bag.’ Turns out they aren’t all bangers. Well, to me they are. The hard part is convincing everyone else they’re worth checking out.”
He kept at it, though, releasing albums from major Minnesota bands like the Blind Shake, Gay Witch Abortion, and Hammerhead, while gaining a rep among musicians as a guy who knew his shit in an industry where that was less common than you’d expect.
“This may surprise you but in the Year 2026, most label heads don’t know anything about music,” says Eddie Gobbo of the Chicago-based band Something Is Waiting, which has released four albums on Learning Curve. “They also look at their audience as knowing even less than them. It wasn’t always this way though and in that sense Rainer Fronz is a throwback. He’s really the smartest OG in the room.”
“He really embodies this quiet, sincere fortitude of community through the most ear-bleedingly loud and chaotic music a girl could dream of,” says Laura Larson of Minneapolis’s Scrunchies, who released their latest album, 2024’s Colossal, on Learning Curve. She echoes Gobbo’s comment about Fronz’s musical smarts and adds, “Also he’s fun to gripe about the Timberwolves with.”
After that, Caterwaul came about from discussions with Neutron. “I had talked with a lot of people over the years about doing something like it. I guess Conan was finally the guy crazy enough to push me, or convince me, to go along with it,” Fronz says.
The original festival was planned—as in all but ready to go—for 2020. Three guesses why that didn’t pan out. But in 2022 it was up and running.
“The idea works because now I can jam 85% of the bands I want to see into one weekend and not go out for the rest of the year,” Fronz says. The joke here is that he’s not joking, not really.
While Fronz was accomplishing all this, his heart was operating at about 15% of what it should have. The bout with pneumonia resulted in heart failure, and in 2013 he had to get a pacemaker to regulate his arrhythmia. Then in 2020 came his Left Ventricle Assist Device (LVAD), which zaps his heart back into rhythm.
To hear Fronz describe it, an LVAD is not a pleasant experience. “The best way I could kind of describe it is like, you know those like massive professional photography bulbs, when they go off? It’s like that energy, that's what it kind of feels like but it's inside your body and there's like no real escape. So it's just like ‘Bam!’ It's like getting hit like that.” Imagine spending your life knowing that at any minute you could get an internal electric shock.
In any case, Fronz has known he’d have to swap out his bum ticker for a while now. He’s been on the cardiac waitlist since the fall of 2024, and his wait has been slightly extended by the fact that Fronz has an O-positive blood type, which narrows down his available hearts.
You don’t want any part of your body to stop working, but if a major organ has got to fail you, at least a heart is a mechanical device that medical professionals have somewhat mastered. There were 4,092 heart transplants in the U.S. in 2023, more than ever before, with a massive reduction in deaths for patients on the waitlist. Despite this growth the success rate remains in the 90% area. And Fronz is in one of the best places for it—Fairview bills itself as one of the “longest running transplant providers,” and its reputation in the field is stellar. (I sure hope I don’t jinx him here.)
Waiting for a heart, Fronz has had time to think about how metaphorically loaded the operation is. The heart is the seat of passion, of vitality, after all. And then there are the weird stories, like one Fronz heard from a cousin.
“A friend of hers got a heart transplant,” he tells me. When the transplant patient met the donor’s wife, she asked to touch his chest and feel the heart.
“And he's like, ‘Yeah, that's copacetic,’” Fronz continues. “And then she's like, ‘Oh my gosh, like do you say that all the time?’ He's like, ‘No, I never say that actually.’ Because that's apparently what her husband who donated the heart used to say all the time."
Fronz is a bit skeptical of this tale, but he’s heard plenty of similar ones. “You hear about how the donor was a person who ate this certain food and the person who received the heart never used to eat that food. Now they eat it,” he says.
That raises a disturbing question that I have to ask.
What if you get a serial killer's heart? And next thing you know, your wife is like,"Why are you holding that knife like that?"
“Yeah I'm like burying bodies in Minnehaha Falls—oh crap, I just gave it up. Damn it. I have to find a new spot now.”
You'd have a great defense. You'd be like, "It's not me, it’s the heart”
“And that guy's already dead.”
Fronz is currently the oldest person awaiting a heart in his ward. In the grand scheme of life, 50 isn’t old old (as I keep telling myself at 56). But it’s old enough that your cultural references don’t necessarily translate as universally as they once did, as he recently learned after watching a CNN story about Kid from Kid ‘n Play getting a heart transplant.
“I was like holy crap, I can't believe I'm watching this,” he recalls. “That’s going to be me. I gotta tell somebody. First I ask my nurse, ‘Do you know who Kid is from Kid ‘n Play, like you know, like House Party? The guy with the tall hair?’ She's like, ‘I don't know who you mean’ and finally I had to get a doctor to tell.”
And a heart operating at 15% can certainly make you feel old. Fronz is currently anticipating the burst of energy that will come with a new-used blood-pump functioning at 60% in his chest. “People who have had a transplant say the amount of energy and essentially life you'll feel is amazing,” he says.
And he has plans. In the future, he’d like to expand Caterwaul to take in other styles of music, to have them interact and crosspollinate in a way more common a couple decades ago.
But for now he’s stuck on the sidelines, ticking off the acts he’ll be bummed to miss this year: a band from Baltimore called Muscle (“this spazzy kind of noisy punk rock”), South Carolina’s Art Star, the recently reunited Louisville hardcore vets Coliseum.
But he’s found others to fill in for him. He’s got his tween daughter Iris handling Learning Curve’s administrative tasks. He tells her: "OK, we need to go get this record, here's how you print the postage, here's how you put the boxes together."
The task-mastering doubles as father-daughter bonding time. Incidentally, per Scrunchies’ Larson, “Iris is a fantastic drummer and the coolest 12 year old I know.
For most of us, an upside of heart surgery is getting a cool scar, but Fronz already has one of those from his cardiac implants. Still, he has an idea: “Maybe I can ask them to do a diagonal cut this time so I can have an X on my chest.”
Caterwaul
With: Full lineup here
When: Friday, June 5–Sunday, June 7
Where: Zhora Darling, 509 First Ave. NE, Minneapolis
Tickets: $50 Friday; $70 Saturday or Sunday; $150 three-day pass; more info here
