Of all the Minnesota music acts played most heavily on the Spotify streaming service — including Prince, Trampled by Turtles, Semisonic and Soul Asylum — it’s safe to assume the O’Neill Brothers are the only ones who got their start performing at J.C. Penney stores, craft fairs and their mom’s red-hat club.

“We went out and listened to what that audience wanted to hear,” Tim O’Neill said.

“That audience” would be older women. While most working musicians try to stay hip to what the kids are into, Tim and his kid brother Ryan have made a good living for a quarter-century by understanding what their mom, Kathleen, and her friends want to hear.

Years ago, a woman at Shakopee’s big autumn craft fair asked the O’Neills if they had any Christian music CDs.

“Our next CD was a Christian music CD,” Ryan recounted. “And it did really well.”

They’ve released more than 50 albums total, including collections for weddings, funerals, nap-time and (ahem) romantic activity. They’ve charted high several times on Billboard’s New Age music chart. They’ve employed three to five staffers over the years.

Just last weekend, the siblings — both in their late 40s — were inducted into the wholly unofficial but still complimentary Minnesota Music Hall of Fame in New Ulm alongside Soul Asylum.

As old-school as they’ve been, though, the big surprise with the O’Neill Brothers is how dexterously they pivoted to music’s digital streaming era.

CD sales have fallen to the point where the brothers can’t even give some discs away — seriously, they’re looking for hospitals, hospices and senior homes to donate them to. But their attentiveness to their audience and willingness to adapt have boosted them into the now-dominant streaming world, with a foothold that even platinum-selling rock stars would admire.

The O’Neills came in at No. 4 on Spotify’s list of its most-played artists from Minnesota (behind Owl City, Prince and Atmosphere, in order). When the list came out a year ago, City Pages declared the O’Neills a “WTF entry.”

They’ve also racked up tens of millions of plays on other streaming services such as Apple Music and Amazon Music.

“We found a niche a long time ago,” Tim said, “and it’s just a bigger niche now in the global market.”

Of course, anyone who’s followed the recording industry’s woes knows the payoff from streaming is minuscule compared with album sales. Most musicians have offset that by gigging more, but with four kids at home Tim has scaled way back on their performance schedule, especially compared with their busy mid-2000s itineraries when they toured as ’80s teen pop star Debbie Gibson’s accompanists.

You won’t catch these fellas complaining, though.

“We get it: Musicians who used to sell CDs for $10 to $15 are now making a fraction of a penny off a listen,” Tim said. “That’s really been a blow to the ego for a lot of musicians.”

These guys set their egos aside long ago, though — “in the dress aisle at J.C. Penney’s,” Ryan cracked, harking back to some of their earliest gigs.

As Tim put it, “It was always less about our name, the O’Neill Brothers, and more about if somebody is getting married, we give them wedding music that’s easy to find. Or if someone just had a baby, they don’t care who’s making the lullaby music.”

That’s especially paid off in recent years via international streams: “Where we used to sell maybe a dozen lullaby CDs at a craft show, we’re now getting millions of parents streaming our lullabies around the globe,” Tim said.

• • •

Rock stars the O’Neills most definitely are not.

Even when they were hanging out recently in the ultra-cool recording studio where the Trashmen and Replacements made some of Minnesota’s most famous rock recordings, Tim and Ryan could have been easily mistaken for pastors, or quilt salesmen, with their polite manners and sunny dispositions.

“We genuinely love playing piano for people, or else we wouldn’t be able to play 10 hours a day” at a craft fair, Ryan said from the couch inside the control room at Creation Audio in south Minneapolis, formerly Kay Bank Studio.

They’ve recorded nearly all of their albums at Creation, using hi-fi equipment and low-lit candlelight. “Instrumental records really have to sound good to stand out,” Tim explained.

Studio owner Steve Wiese said he’s impressed by the O’Neill brothers’ “ability to always look ahead.

“It’s easy for musicians to get stuck in what they’re already doing, but they’ve always seen where the fork in the road is and taken the right path. They’re very talented musicians but also very smart businessmen.”

Notre Dame grads — Tim’s the one with the business degree, Ryan is now a Realtor on the side — they grew up in the idyllic main-street town of New Prague, 45 minutes south of the Twin Cities. Their late father, Bob, bought a piano for the family even before he had a family, using one of his first paychecks out of law school.

“He could deal with a death in the family or the death of a cow,” Ryan proudly quipped of their dad’s career as small-town lawyer.

All six O’Neill siblings took piano lessons, but the youngest pair were the most musical. Ryan also played trombone in concert band.

Tim, it turns out, played in a rock band in Minneapolis before becoming a piano soloist. They were named Hyde & Seek and covered “everything from Styx to Billy Joel to the Dave Matthews Band,” he reported.

Hey, for a guy who’d soon be gigging at J.C. Penney stores, that was pretty edgy stuff.

“We played Penneys from Maui to the Bronx” in the late ’90s, Tim bragged. They shifted to craft shows as their mainstay after Penney execs decided their department stores weren’t fancy enough to have serenading pianists.

“We saw our mom and her friends going to the craft fairs and followed them there,” Tim said. “They draw like 100,000 people over one weekend, mostly women in their 50s and up, all looking for unique, handmade holiday gifts.”

Even the crafters have stopped buying CDs, though.

The O’Neills still sell a few discs per day off their website Pianobrothers.com or Amazon; type in “piano lullabies” or “piano Christmas music” and their albums come up. But for the most part, they concentrate on streaming. They’ve enlisted other instrumentalists to help them churn out material, such as a recent album of Elton John interpretations that went straight to stream.

As proud as they are of their modernization, the O’Neills also lament the demise of their old business model. They even miss the Penney’s gigs.

“The human side of it is a big part of the enjoyment for us, knowing our music played a role in these people’s weddings or funerals,” Ryan said.

“We don’t have that one-on-one contact anymore,” Tim said. “We’d see a lot of the same women at these craft fairs each year, and then one year we’d meet the daughter, and she’d tell us her mom played our CD over and over in the hospital.

“That was very special to us.”

OK, maybe they actually are rock stars.