Founder and first violinist of the Kronos Quartet, Harrington already had been playing string quartets for a couple of years when, at age 14, "I walked by the globe in our home. And I had this moment when I thought: All the string quartet music that I've ever heard in my life was written by Haydn, Mozart, Beethoven and Schubert. And they all lived in Vienna, Austria.

"It didn't take a lot of thought to realize that there are a whole lot of other cities in the world, a whole lot of other countries. ... Other languages. From that point, I realized what I wanted to do. I wanted to learn more about music from around the world."

Harrington has done more than just learn. The San Francisco-based group he launched in 1973 has become one of the world's most visible and influential contemporary classical ensembles — a conduit through which the music of many cultures and voices reaches new ears.

They've done it through a prolific recorded output (59 albums in 43 years) and concerts like the two that the group will present Saturday and Sunday at St. Paul's Fitzgerald Theater.

Saturday's program, "New Global Voices," features works from India, Indonesia, Iran, Mali, Serbia and South Korea, as well as the United States and Canada. Then on Sunday, the foursome presents "Old Friends," with music by contemporary composers whose works the Kronos has premiered over the decades, including frequent collaborator Terry Riley, Philip Glass, Afropop star Angelique Kidjo and Bryce Dessner of rock band the National.

What set Harrington on this path of bringing living composers' music to the world?

"It was August of 1973, and we had the radio on late at night," he said. "All of a sudden, there was 'Black Angels' [by George Crumb]. It changed my entire life. I'd never heard a string quartet sound that way.

"The next day, I found out who George Crumb was, who his publisher was. I called the publisher in New York. A few days later, I had this score, and it was unlike any music I'd ever seen.

"In addition to opening my ears to new sounds, it felt like music that could respond to the war in Vietnam. It felt to me like: Now I have a voice. I have a piece that reflects how I feel. … After looking at that score, I realized: Well, there's no way I can do this without getting a group together. So that's why I started Kronos."

It wasn't long before the group found an audience of adventurous listeners, becoming among ambassadors for what came to be called "new music."

They were musical guests on late-night TV. They serenaded Big Bird on "Sesame Street." And they were embraced by hipsters as the coolest of string quartets — a defiant departure from the typical tux-and-gown-clad purveyors of Haydn and Beethoven.

Kronos performed at their 2018 Kronos Festival in San Francisco. (Evan Neff/The Minnesota Star Tribune)

Walker Art Center helped with that hipness quotient, hosting the group 19 times between 1985 and 2011. It's presenting this weekend's concerts, too, along with the Schubert Club and Minnesota Public Radio.

The pieces being performed are part of the quartet's "50 for the Future" project: They've commissioned 50 composers to create new works to which online audiences are being given virtually unlimited access. Musicians can find not only recordings of the pieces at KronosQuartet.org, but also scores so they can play the music themselves.

"There's a difficulty for many players and audience members to have access to music from various places in the world," Harrington said. "I mean, you can go to a music library and find no music by an African musician, for example. You would not be able to find 'Black Angels.'"

The quartet's reach to remote areas might be best exemplified by its 20-year relationship with Tanya Tagaq, an Indigenous throat singer from Canada's far-north Nunavut territory. Harrington first heard her on a world music compilation while flying over Greenland.

"I just about jumped out of the plane," Harrington said. "I must have listened 30 or 40 times from Greenland to San Francisco. I realized that, if something hits me like that, I have to find the musician. It took a while, but I figured out how to reach Tanya.

"I explained what Kronos does and what we were thinking about. And I said, 'You know, Tanya, I've never heard a singer before who I feel actually has a string quartet in her throat. But I think you do. … I really like the notes you make.' And she kind of giggled and said, 'What's a note?' And I realized: I don't have any idea what a note is."

Tagaq is among the "old friends" having work presented Sunday.

Next year the group marks its 50th anniversary; three of its four members have been in the group since 1978. And Harrington is as excited and enthusiastic as ever.

"I would like there to be lots of 'Black Angels' kind of pieces that, when you encounter it, you don't have any choice: You have to rethink your life and your priorities," he said. "Right now, composers are really digging deep into life and making some fabulous new experiences for all of us."

Kronos Quartet
When: 7:30 p.m. Sat.-Sun.
Where: Fitzgerald Theater, 10 E. Exchange St., St. Paul.
Tickets: $28-$48, first-avenue.com

Rob Hubbard is a Twin Cities freelance classical music writer. wordhub@yahoo.com.