‘Is She Sure?’ How the Breeders Joined Olivia Rodrigo’s Guts Tour.

Olivia Rodrigo remembers her life in two parts: before she heard the Breeders’ “Cannonball,” and after, she told the crowd at Madison Square Garden on Friday night, when her Guts World Tour arrived in New York.

And that is how the ’90s alt-rock idols came to play the New York arena for the first time last week, 31 years after that song from their platinum 1993 album, “Last Splash,” charted on Billboard’s Hot 100.

Rodrigo’s camp initially approached the Breeders in September about opening some dates on the tour supporting her second album, “Guts.” “My first reaction was, Wow, that seems kind of odd,” the band’s bassist, Josephine Wiggs, said in an interview. “But after I’d thought about it for a while, I thought, ‘That’s actually really genius.’”

Kim Deal, the singer-guitarist who leads the band with her twin sister, Kelley, said she was surprised when they got the invite. “I’d heard ‘Drivers License,’ and I liked that a lot,” she said, referring to Rodrigo’s breakout 2021 smash.

Kelley wondered if it might be a mistake. “I thought, ‘Is she sure? Do they really mean us?’”

But Rodrigo made her enthusiasm clear when the shows were confirmed, reaching out personally to share her excitement. “She texted each one of us individually,” Kelley recalled.

“And said, ‘Really happy to hear that you’re going to do this,’” Wiggs added. “Very classy.”

Aside from Kim, who played Madison Square Garden in 1992 when her earlier band, Pixies, opened for U2, no one in the group had ever performed at the venue before. Kim hadn’t been back since, and said she had no memory of that previous gig: “I usually remember the bad shows, so it’s a good thing that I really don’t remember that one.”

With the first date in the books, the Breeders spent part of Saturday afternoon glimpsing Rodrigo’s soundcheck — she was belting “Ballad of a Homeschooled Girl” to an empty arena — and then briefly chatting with her. “So easy to talk to!” Kim reported as the Breeders headed up to the stage to adjust their own amps and pedals. The lights were up; two men vacuumed the previous night’s pink and purple star-shaped confetti.

“How about we do a piece of ‘Cannonball,’ like when everything comes in?” Kim asked the band, which also includes the drummer Jim Macpherson. They had already tested the distorted ahh-ooohh-ahh vocalizations that open the song. Kim blew a whistle to emulate the record’s microphone feedback.

Rodrigo was born a decade after the release of “Cannonball,” but the 21-year-old heard it as a teenager and remembers “instantly falling in love with the Breeders,” she wrote in an email. “I thought Kim was the coolest girl in the world,” Rodrigo said. “I’m very inspired by them and everything they stand for. They are absolutely iconic, and playing these shows with them has been a surreal honor.” (The Breeders have joined the tour for four shows at the Garden that wrap on Tuesday, and four more at the Kia Forum in Los Angeles later this summer.)

Mischief, wryness, confidence and camaraderie feel encoded into the poised riffs and bass line of “Cannonball,” and it’s easy to imagine girls gently headbanging along to it for eternity. Rodrigo went louder and crunchier on “Guts,” long inspired by artists who are “not trying to recreate a version of rock music that guys make,” as she told The New York Times last year.

Soundcheck proceeded like a supercut. “Should we do half of ‘Do You Love Me Now’?” Kim asked before crashing the song open and letting its twin harmonies ring out. “A little piece of ‘Drivin’ on 9’?” signaling the aching country tune. “Should we throw in ‘Gigantic’?” Kim asked before unleashing the titanic anthem she co-wrote and sang as a member of Pixies. (She dedicated its “big, big love” to Rodrigo during the show.)

Earlier, the band sat in a green room processing its Guts experience so far. Kelley had been impressed by the emotional arc of Rodrigo’s songs the previous night. “I was texting somebody, ‘I’m so empowered right now!’” She later reached out to praise Rodrigo’s voice as “really special,” observing, “Her tone and control are spectacular!”

“She performs with a really good sense of humor,” Kim added.

Wiggs said she could hear some Breeders commonalties in a Rodrigo chord progression, while Macpherson detected a bit of the band in “Jealousy, Jealousy,” from her first album, “Sour.” “The bass riff was almost like a ‘Hag,’ ‘Hellbound’-ish kind of thing,” he said.

The Breeders expressed shock at how young Rodrigo’s fans were, and the collective decibel of their screams on Friday night. “You’re going to be surprised by how loud it was,” Kelley said. Weren’t their own amps loud, too? “Not louder than 30,000 tweens,” she said.

Kim roasted her bandmates for withholding stage banter the night before. “Looking out at the sea of 7- and 8-year-olds, I had no idea what to say,” Wiggs said, deadpan. “I could just about manage to say something to people who are obviously teenagers. I was like, OK, maybe I’ll try to make eye contact with the dads.”

The Deal sisters are no strangers to parental accompaniment at gigs. “My dad used to have Ray Charles in his headphones, watching us play, when he drove us around in the r.v. with Nirvana,” Kim said, referring to the band’s 1992 tour with what was then the biggest band on Earth. “He’d have his cassette Walkman,” Kelley added. “He was a big supporter, but he’d heard us a million times.”

In Kurt Cobain’s liner notes to Nirvana’s 1992 compilation “Incesticide,” he detailed the recent life experiences that had meant the most to him since “becoming an untouchable boy genius,” including “playing with the Breeders” on the list. “Nirvana and Foo Fighters would really curate their opening bands, which is I think what Olivia is doing in a way, curating new music that she wants fans to get to know,” Kelley said.

Most of the young people watching from the front rows on Saturday were not familiar with the Breeders — who are all in their 50s and 60s — though there were exceptions. “My parents know who they are!” exclaimed an 18-year-old fan named Mack. “My dad said they had some jams back when he was younger. He didn’t know if I would like them, but I trust Olivia.”

Another fan, Elle, 16, was with her father, who saw the Breeders at Lollapalooza alongside Smashing Pumpkins and the Beastie Boys. “For me, this was really cool,” he said. “I don’t know the tour’s other openers as well, but I’ve loved the Breeders since ’94 when I saw them last.”

Rodrigo’s fans were decked out in sparkling skirts, purple bows and platform boots in honor of their heroine, who took the stage in a series of short, glittering skirts. The Breeders are known for more understated sartorial choices. Had they given any thought about to what to wear?

“I sent out a ‘help’ text to a friend of mine,” Kelley admitted. “I said, I’m trying to upgrade my look from my T-shirt and jeans that I typically wear, but staying in my comfort zone. He said, ‘I find glitter or sequins to always be the answer.’ I just waited for him to laugh or something. That was no help to me at all. So I went with a T-shirt and jeans.”

“Like she’s been dressing since seventh grade,” Kim said.