Chris Thile holds a valued musical treasure in his hands, and I'm not talking about the 1924 Gibson F5 mandolin that he reportedly plunked down close to $200,000 for in 2007.

No, not that rare instrument signed by Lloyd Loar - the Stradivari of mandolin makers - that is the same model bluegrass originator Bill Monroe played.

The cherished treasure whose fate is now under the control of the 35-year-old virtuoso is A Prairie Home Companion, the public-radio institution founded in 1974 by Garrison Keillor, which airs at 6 p.m. Saturdays on WHYY-FM (90.9), as well as on more than 600 North American stations.

The love-him-or-hate-him Lake Wobegon storyteller with the breathy baritone - who once inspired Homer Simpson to yell at the TV, "Be more funny!" - hung up his trademark New Balance hosting shoes in July with a farewell broadcast of the show before 18,000 fans at the Hollywood Bowl in Los Angeles.

Although Keillor, 74, is gone, Prairie Home rolls on. Thile (pronounced THEE-lee) made his first appearance as a 15-year-old bluegrass prodigy in 1996 and has guested many times since as a solo artist or with his bands Nickel Creek and Punch Brothers.

Last year, the founder, who is still credited as a producer of the show, appointed Thile as his successor. The singer made his debut as permanent host last month with a show that featured musical guests Jack White and Lake Street Dive, and comedian Maeve Higgins. He has done two more performances since at the home base in the Fitzgerald Theater in St. Paul, Minn.

On Nov. 12, Thile will take the show on the road for the first time, when Prairie Home happens live at the Academy of Music in Philadelphia. The guest list reflects the balance of music and spoken word that the amiable and inquisitive Thile is after, with ace Americana songwriter Jason Isbell, Beninese singer Angelique Kidjo, and former American poet laureate Billy Collins. The show will do other on-the-road dates through February, including New York on Dec. 3 and 10.

So, how does it feel to take over a much-beloved broadcast institution? To be the upstart Stephen Colbert to Keillor's David Letterman? The Trevor Noah to his Jon Stewart?

"I'm having so much fun," Thile says, on the phone from his current hometown of Portland, Ore., where his actress wife, Claire Coffee, works shooting the supernatural NBC cop show Grimm. They have an 18-month-old son, Calvin.

Thile sounds somewhat frazzled, though he was talking during his first week off between shows, but he says it like he means it.

"It's a tremendously exhilarating thing to do with one's week," he says of preparing and performing the show, which reaches 4 million listeners. It airs live on Saturday nights, though Thile is doing only 13 shows his first year. Rebroadcasts of classic episodes will air on other weeks. (Episodes can be streamed at prairiehome.org.)

"I do a little bit of work on the flight home on Sunday and think about what I might write about. I try to have a song" - he writes a topical one every week - "in enough shape to communicate it to the house band on Wednesday. I start to write my little opening remarks, and I revise them over the next couple of days. And then there's a new specific verse in the theme song that I might work on right until I go on stage.

"It's work that demands one be present," he says. "Especially in this day and age, where there's so much temptation to check Twitter, check scores. Ostensibly, the world at your fingertips, just behind that little screen. And you start hunching over, and you're never actually where you are."

Doing the show, he says, "is such a lesson in trying to maximize your day. And just to know the red light is going on and we have two hours to fill. It's a welcome wolf at the door. There's no way to be overly precious about something, or wring the life out of it, which I can do sometimes, being a perfectionist. You have to go with the first impulse that yields real results."

Speaking of checking scores, Thile was a star baseball player as a teen and is an avowed fan of the World Series champion Chicago Cubs, whom he grew up watching on nationwide cable channel WGN during a California childhood split between the coastal town of Oceanside, where he met the Watkins siblings who became his bandmates in Nickel Creek, and the mountain town of Idyllwild, where his family moved when he was 4.

He was interviewed from Portland two days after watching the Cubs win Game Five of the World Series at Wrigley Field, and he did not know whether he would be plunged into depression or sublime excitement in the coming days. "That's the nice thing about Prairie Home," he says, in angsty anticipation. "It gives one a nice outlet for feelings. For all the feelings. There's a place for elation and a place for sorrow. Whatever I've got, I've got a way to get it out."

Expect some national pastime talk from Thile - who has no plans to try to re-create Keillor's Lake Wobegon or "Guy Noir, Private Eye" skits on the show - when Prairie comes to Philadelphia. His great-great-great uncle was Samuel "Big Sam" Thompson, one of baseball's great pre-Babe Ruth power hitters, who played for the Phillies from 1889 to 1898. That's a point of pride on his mother's side of the family.

When he was growing up, Thile, who won a MacArthur "genius" grant of $500,000 in 2012, says, "Prairie Home was a pillar of our week. We spent a lot of time in the car, driving to bluegrass festivals. The way that Garrison engages an audience deeply informed the way I go about attempting to make a connection with whomever I'm performing for."

Keillor praises Thile's "curiosity and inventiveness." He told the Minneapolis Star-Tribune this year: "He plunges in and engages the question, and out of that engagement comes invention. He is fearless."

Thile calls the Philadelphia lineup "a dream show. To have a wonderful American singer-songwriter like Jason Isbell and then Angelique Kidjo, who is just explosive and a shaking-the-foundations-of-the-earth kind of a singer." He's psyched that a personal hero, fiddler Stuart Duncan, will be in the house band, "and then Billy Collins, one of the world's greatest poets. There's a great quote about him, 'putting the fun back in profundity,' and I wholly subscribe to that evaluation."

The show, which every week will feature Thile and band doing a by-request cover song - last week, during a Halloween episode headlined by jazz adventurer Esperanza Spalding, it was Michael Jackson's "Thriller" - will have an emphasis shift.

"Because of the format that Garrison imagined, it's a place that rewards open-mindedness," he says. "Now, I'm a musician hosting the show rather than a writer, so there's a natural focus pivot. But the overall dimensions of the show haven't changed much in terms of music and spoken word."

Thile's musical taste is catholic: He's performed Dizzy Gillespie's "Salt Peanuts" and Kendrick Lamar's "Alright" on the show, and has a new album on the way with the Punch Brothers, as well as a fresh set of Bach recordings with bassist Edgar Meyer and cellist Yo-Yo Ma. There's also a collaborative project with jazz pianist Brad Mehldau.

"Moving the show forward," Thile says, "I want to make sure that it represents what's happening in the world musically and comedically speaking. We'll keep trying to fling that door open wide to whatever is there."

215-854-5628

@delucadan

PERFORMANCE

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A Prairie Home Companion

With Chris Thile, plus Jason Isbell, Angelique Kidjo, and Billy Collins, at 5:45 p.m. Nov. 12 at the Academy of Music, Broad and Locust Streets.

Tickets: $49-$79.

Information: 215-893-1999 or kimmelcenter.org.

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