When Penelope Lowenstein received invitations to see Nora Cheng and Gigi Reece, her two best friends and Horsegirl bandmates, graduate from their respective high schools, she was faced with a dilemma: Both events were scheduled for the same day. One of the upsides to the pandemic, however, is that virtual options are increasingly available, so she did what any good friend would and figured out a way to celebrate them simultaneously. While Reece’s high school graduation unfolded on her phone, Lowenstein hopped in the car to catch Cheng’s ceremony in person. That’s when their song “Ballroom Dance Scene” came on the radio.

Statistically, the chances of that happening are actually pretty high. SiriusXMU played “Ballroom Dance Scene” 175 times in the past two months, making it the 15th most-heard song on the channel, beating out singles by Courtney Barnett, Caroline Polachek, Rostam, and Girl In Red. “It was a beautiful moment of watching my friends graduate at the same time to the sound of our own music,” laughs Lowenstein. “What’s even weirder is that it was getting played on the radio a lot then, so it almost felt normal.”

On first listen, “Ballroom Dance Scene” sounds like the type of song your local college station would play at 10PM on a snowy weeknight in the ’90s. A modest drum beat and whispery vocal coos prop up in the background while Lowenstein and Cheng trade off speak-singing verses about seeking and offering reprieve during trying times. A thin synth part whirls in the distance, guitar feedback yawns into frame, and bass slowly picks up the pace, swirling everything together like a gorgeous crescendo from Electr-O-Pura.

Hearing your own song on the radio before you’ve even graduated high school isn’t normal, of course, but nothing has been normal about the past year, especially for Horsegirl. Lowenstein, Cheng, and Reece all grew up in Chicago but attended different school districts. During the pandemic, they hung out at each other’s houses while attending classes virtually, a setup that allowed them to pretend to be classmates for the first time. Afterwards, they would grab their instruments — Lowenstein and Cheng on guitar, Reece on drums — and start hashing out new music. Looking back now, they can’t imagine pulling off their studies and songs to that same extent if it weren’t for the pandemic.

The trio’s route to friendship, never mind forming a band, came about unexpectedly, too. After tapping into local resources like Old Town School Of Folk Music and Girls Rock Chicago when they were young, they finally crossed paths when enrolling in an extracurricular music program in 2018. It was there that they learned the “important things,” like how to play with other musicians, run a rehearsal, give notes, soundcheck, and loop your cable through your guitar strap. Outside of the program, they started attending concerts together, including one fateful warehouse show where all three of them showed up to watch local bands but quickly got caught up discussing their favorite Matador acts, swapping songs, and making a pact to jam sometime. Near the end of 2019, Lowenstein, Cheng, and Reece transformed from show buddies to the unshakeable friend group that is Horsegirl.

“The crazy thing is that we had seen upperclassmen and people from our music program playing shows and starting bands on their own, so it seemed like a very feasible thing to do,” says Lowenstein. “Whenever I hung out with Nora, my dad was so excited that I had found a friend that I loved and who would play music with me for hours in the basement. Once when he was driving, he said we needed to start a band. It was not my dad’s idea to start the band, because we always felt like it was on the horizon, but that was an extra push of confidence to decide to write our first song.” That wound up being “Sea Life Sandwich Boy,” a noisy slice of indie pop à la Electrelane. They bashfully label it as “not a bad first song” before admitting it’s since become an “all-time classic.”

Horsegirl’s lone EP, Ballroom Dance Scene et cetera (best of Horsegirl), features the two previously mentioned singles alongside “Forecast,” a five-minute jolt of art-rock they describe as “Sonic Youth worship.” Every song Horsegirl pen is the result of an equal, collaborative process. Apparently it’s all they’ve ever known, as their only attempts at songwriting have always been as a unit. “I think I’ve just started to learn that not a lot of bands write this way,” says Lowenstein. “Sometimes someone will have a small part that they send to the group chat, and then they explain what they want it to be, like, ‘Life Without Buildings + Broadcast.’ The rest of us say okay, head to the basement, and try to figure it out. It’s a whirlwind — like yesterday, where we’ll be downstairs working on a new song all day and not even realize it.”

The signature trait linking Horsegirl’s songs together is a purity in their approach to music at large. Their days are spent obsessively falling down music rabbit holes and sharing documentary clips in their group chat, which reads like a digitized scrapbook cataloging the timeline of their ideas in real time. Horsegirl’s biggest influences come in phases: drummers who stand while playing (Gang Of Four and the Velvet Underground in particular), Slowdive’s detuned guitars (which were copied from My Bloody Valentine), Belle & Sebastian’s moody lyrics that avoid being full-blown emo (“their Pitchfork documentary is essential”), and vintage videos of artists they love performing in random places (Dear Nora, the Beets, Charlie Megira, and Deerhoof). Hearing the three talk about music is like being transported back to your early teens where you hear a band for the first time and gleefully research them, amazed that they can capture such a strange sound or put your emotions into words so effortlessly. It’s no wonder Matador rushed to sign Horsegirl given they’re following in their labelmates’ footsteps.

Earlier in July, Horsegirl left Chicago to embark on their first-ever tour. The trio barely had time to process pre-trip nerves, and they didn’t know what to expect upon returning home either: exhaustion, rejection, or, worst of all, annoyance at one another? After all, “touring” is another name for playing the same songs consecutively each night to strangers you don’t know in cities you’ve never been to before. Although it was short, clocking in at just four dates in the Midwest, Horsegirl’s debut tour was a success, both for fans and the bandmates themselves. “Turns out we love one another,” says Reece with faux surprise while imitating the shrug emoticon.

Armed with a cautious perspective, Horsegirl looked forward to potentially playing empty venues on the tour. In their eyes, it would have been a great way to rehearse in different spaces free of pressure. “Who’s going to come see us on a weeknight in Madison?” reasons Lowenstein. As it turned out, a lot of people. On that first night of the tour, one fan revealed he flew out from San Francisco to see Horsegirl and they bonded over their favorite Stereolab songs. The next night, Lowenstein was asked to sign someone’s shirt and she froze, realizing that she didn’t know what her own signature even looked like. Fans regularly sang along to “Ballroom Dance Scene” and leaned across the stage to snatch a setlist once their performance ended, leaving Horsegirl dumbfounded each time. “We thought these would be practice shows,” says Cheng. “But so many people were there that suddenly they were very real shows.”

When Horsegirl returned to Chicago, they were greeted by a sold-out hometown show at Schubas. A line snaked around the block, full of friends, family, and fans the band had never met before. After years of attending concerts at Schubas, they were stunned to not only fill the place up, but to get an encore chant they never imagined would happen. It’s natural to wonder what the crowd will be like when Horsegirl take the stage at Pitchfork Music Festival on Sept. 11, too. It’s their biggest Chicago gig to date, their favorite festival to attend as fans, and so far “everyone they’ve ever known” plans on going.

“It feels like I’m getting ready for my wedding,” laughs Lowenstein. “My grandparents are going, my friends are going, my teacher will be there, plus I have to pick the perfect outfit?” Normally playing at a music festival you adore would be nerve-wracking to a band of freshly minted 18-year-olds and one 17-year-old, but Horsegirl seem more excited than anything else. They’re naturals when it comes to playing live — they did meet at a music program focused on live performance, after all — and they’ve got the hang of debuting new material onstage courtesy of their tour. “We’re kids writing songs that we love who are just trying to do our thing,” explains Cheng. “We’re lucky to get to play and we’re going to lose our minds, but in the fun way where we’re grateful to get to be there at all.”

That stance extends to Horsegirl’s sudden blow-up, too. For a trio of teens with a three-song EP to their name and nothing else, they’ve gotten extensive coverage from music publications and radio stations that most groups dream of. It hasn’t pumped up their egos, freaked out their anxieties, or straddled them with weighted expectations. Horsegirl are first and foremost music fans who are thrilled to learn about and namecheck the bands that preceded them, the music styles that have escaped them, and the sheer joy of hearing songs that electrify your emotions. If anything, the hardest part of breaking out into the national music scene is comprehending that their band exists in the same realm as bands they adore.

“The best way of describing [where we’re at mentally] is that when people ask to interview us, we never have to ask who that is. Stereogum, Pitchfork, NME — trust us, we know. We read these sites all the time,” says Reece. “It feels like I should be feeling all of this pressure because of that, especially when we only have three songs out and we’re making our first album, but I feel really good. I have a lot of faith in what we’re doing, and it’s cool to see other people think so, too.”

Horsegirl play the Green Stage at Pitchfork Music Festival in Chicago’s Union Park at 1PM on Saturday, 9/11.