RAY SUAREZ: Next: a mandolin virtuoso who defies musical boundaries. Chris Thile has recorded bluegrass, country, folk, and jazz. Tomorrow, he releases a new album of Bach sonatas. Jeffrey Brown has our report.

JEFFREY BROWN: The final movement of Sonata No. 1 in G Minor by Johann Sebastian Bach, written in the early 1700s for solo violin.

Now this and other works by Bach are being given a new treatment for the mandolin by one of that instrument's modern masters, Chris Thile.

Why Bach? Well, when we met recently at the Rockwood Music Hall, a tiny bar near his home in Manhattan, Thile told me, it's simple.

CHRIS THILE, musician: When you talk about Bach, I mean, you're talking about the greatest musician who ever lived. You will find...

JEFFREY BROWN: You think that?

CHRIS THILE: Absolutely.

Most of my buddies and great musicians that I talk to, people are pretty -- it's like Bach, and then you start having arguments.

JEFFREY BROWN: But once those arguments start, Thile says, the issue is musicianship, not genre.

At just 32, Thile, who often sings as well as plays mandolin and guitar, has already made a name for himself as a genre-bender. In his best-known format, bluegrass, he and his colleagues in the band Punch Brothers have expanded the form well beyond traditional tunes.

He's also collaborated with classical cellist extraordinaire Yo-Yo Ma in a recording called "The Goat Rodeo Sessions" that won a Grammy earlier this year for best folk album. When the MacArthur Foundation awarded Thile the so-called genius grant last year, it cited his creation of a -- quote -- "distinctly American canon for the mandolin and a new musical aesthetic for performers and audiences alike."

This is a man who clearly loves all kinds of music, and doesn't like boundaries.

CHRIS THILE: They're just not helpful. They don't -- they don't -- if you sit down and say to yourself, I want to write a bluegrass song, instantly, you're limiting yourself.

JEFFREY BROWN: It was bluegrass, though, that started it. Thile, who grew up in Carlsbad, California, began lessons at age 5, formed a band called Nickel Creek with two friends at 8, and released albums with the band and solo at age 13.

He says he loved the challenge of the instrument right away.

CHRIS THILE: It's so precise, painfully precise. Like, you know, you get the plastic pick hitting metal strings, and so there's no doubt when the note happens.

JEFFREY BROWN: And that precision, limiting and freeing, he says, informs his approach to Bach.

So when you're playing your bluegrass music and you start doing whatever, you make a mistake, you just continue, right?

CHRIS THILE: Oh, yes.

JEFFREY BROWN: What about Bach?

CHRIS THILE: In bluegrass, a mistake can become the rightest thing you do.

JEFFREY BROWN: Right, but not with Bach?

CHRIS THILE: Not with Bach.

JEFFREY BROWN: Thile's been playing Bach pieces for himself for years. He's also listened to numerous recordings of great violinists who've taken them on. I asked him to explain what his instrument can bring to the music.

CHRIS THILE: It's easy with these big -- the fugal pieces, where they're all about precision, and these secondary voices come in. There's a third voice.

And I have options there, where violinists have to crunch those things, you know, where you get to these four voice chords and violinists have to go -- and so I might choose to play these -- it's an opening and it's, of course, like, emphasis. But how fun is it then to kind of, like, back off this next phrase? It's almost like this kind of...

JEFFREY BROWN: So, that's how you get out the expression of the instrument, yes.

CHRIS THILE: Yes. You have got this guy going, like, let me tell you something. And then the other guy goes, well, you know, actually...

JEFFREY BROWN: And that's another thing. Thile wants his audience to have a great time experiencing Bach, just as they would anything else he plays.

It's another musical box he doesn't like: the formality of attending a classical music concert and the distance we have put between, say, a fiddle tune and a Bach partita.

CHRIS THILE: Maybe like, you know, something like that. And, you know, that's -- you're not going very far afield there...

JEFFREY BROWN: Not that far off.

CHRIS THILE: ... to get to those two places.

JEFFREY BROWN: Although most people don't think of it that way.

CHRIS THILE: Partially because, like, we're so far removed from someone being in a situation where they could dance to Bach.

JEFFREY BROWN: Thile wants us all tapping our toes and nursing our drinks to both bluegrass and Bach. And he's scheduled to perform both around the world in the coming months.

CHRIS THILE: You want to contribute. You want to make a -- you just want to leave the world with more good music than it had before you got there.

So, if I got to actually make some of it, then I could -- regardless of what comes next, maybe in that last moment of consciousness, I would go, like, you know, OK, OK.

JEFFREY BROWN: This was pretty good.

CHRIS THILE: Yes, not bad.