Mandolinist whiz Chris Thile did not begin his career with an innate love of classical music.

“Until I was 15 or 16, I couldn’t have cared less about classical music,” Thile tells EW. “I grew up playing fiddle tunes where the whole point is getting people’s bodies to move, and I thought classical music was completely divorced from the body.”

Although he had family members who played classical music, Thile had already won the national mandolin championship at age 12.

“I thought I was doing more hip music,” he recalls. “You guys do that powdered-wig music.”

Then his grandmother played him legendary pianist Glenn Gould’s second recording of Johann Sebastian Bach’s Goldberg Variations. “He kicks into that first variation and it just took my head off,” Thile says. “He was playing with as much groove as I’ve heard anyone play with. All of my biases against classical music just went away.”

That early encounter informed Thile’s relentless quest to go beyond conventional musical categories. He spent the next few years playing progressive bluegrass with his Grammy-winning trio Nickel Creek and then the acoustic quintet The Punch Brothers — a featured guest ensemble playing with Gabriel Kahane at the Oregon Bach Festival July 5.

Now 36, the California-born Thile — who plays a dozen instruments and sings — seems equally comfortable playing rock and Bach. He’s made an album of J.S. Bach’s music transcribed for solo mandolin and will soon release an album of Bach’s music featuring bass boss Edgar Meyer and cello champ Yo-Yo Ma (with whom he’s already collected yet more Grammys). And he’s composed a dazzling mandolin concerto that he performed with orchestras including his new hometown’s Oregon Symphony last year.

Thile and his wife, Grimm actress Claire Coffee, bought a house last year near Portland’s Washington Park, where they’re raising 1-year-old Calvin, who enthusiastically helped Thile answer EW’s questions (e.g.,“Being a dad has helped me live a more contrapuntal life,” the 2012 MacArthur “genius” grantee cracked while extracting his toddler from under a table).

Though Thile succeeds Garrison Keillor as host of A Prairie Home Companion this fall, he says the family has no plans to move to Lake Wobegon.

But for more evidence of a tendency to rock, look to The Punch Brothers’ new EP, which covers a song by Portland’s Elliott Smith. And at OBF, Punch Brothers will likely play original tunes from their recent T Bone Burnett-produced recordings, The Phosphorescent Blues and The Wireless, along with covers of classical and other composers. The band seemed equally at home before older classical music audiences at Portland’s Chamber Music Northwest a few years back, as they did serenading twentysomethings last year at Portland’s Roseland Theater in a sold-out show that included music by Debussy and Scriabin.

“We’re five guys who are looking everywhere for great music and are observing that great music tends to exhibit certain qualities,” Thile explains. “To me, a great symphony has more in common with a great fiddle tune than with a bad symphony.”

Thile insists that, for him, there’s no inherent difference between classical and non-classical music. “Whether it’s Debussy and Bartok or The Beatles and Radiohead,” he says, “the greatest instances on both sides of that coin tend to balance the learned and intuitive, and to hold up to the scrutiny of either approach.”

The Punch Brothers play with Gabriel Kahane 7:30 pm Tuesday, July 5, at the Hult Center; $20-$66; college and youth discounts available. See oregonbachfestival.com for ticket info.