Chris Thile is not a genre-hopper. He has travelled a long road from teenaged bluegrass prodigy to garlanded genius of American music. The average performance by Thile (whose surname is pronounced Theelee) may run the gamut from new grass to Radiohead to Bach, but to the California-born mandolin virtuoso it's all just music. So if he hates the term genre- hopper so much, he probably shouldn't have used it himself.

“I know,” he says with a groan down the phone from his home in Portland, Oregon. “I’ve definitely been saddled with that term, due to my omnivorous musical appetite. But I’m pretty convinced that what we call ‘genres’ are formed when a bunch of good musicians copy the work of a few great musicians. Great music is the only genre that actually matters, and the members of that club are far more similar to each other than they are to any genre they might be commonly associated with. So there’s nothing to hop. The idea of flitting from genre to genre as if each were a flower that you were attempting to pollinate is silly to me.”

Whatever he wants not to call it, Thile has shown a healthy disregard for boundaries over the past two decades, and now, at 33 – quite apart from his successful groups Nickel Creek and Punch Brothers – he has close musical relationships with some of the United States' greatest musicians, including the classical cellist Yo-Yo Ma, the avant-garde bassist Edgar Meyer and, now, the acclaimed jazz pianist Brad Mehldau, with whom he takes the stage at the National Concert Hall this weekend.

“I think what people call genre is just a question of orchestration. So, for instance, with Punch Brothers, you look at that band and say that’s a bluegrass band, when really it’s an orchestration choice. I wanted to make music with a banjo player, a fiddle player, a guitar player and a bass player, because we know those instruments better than we know anything else. But the idea that we would then seek to uphold the [bluegrass] tradition is silly. We want to emulate the spirit of those great musicians, not copy their work. Someone like Bill Monroe, for instance, he was an explosively creative dude,” Thile says, referring to the founding father of bluegrass. “He wouldn’t be caught dead just copying the work of the masters past.”

Ocean of music

But times are different. Musicians who have learned their craft in the digital age have instant access to an ocean of music, and that has to be affecting musicians want to sound like.

“That’s exactly right,” he says, “and, you know, just in the same way that the musicians in the hills of Appalachia would be informed almost exclusively by the music that they could find in their own towns and villages, now those same musicians have the internet. Our village now stretches around the globe, and, as dedicated, serious music makers, I think we owe it to ourselves to experience and interact with the width and breadth of music available to us, to learn from it, and to attempt – boldly, bombastically, audaciously – to contribute.”

So for Thile, his collaboration with Mehldau, perhaps the leading improviser of his generation, with a towering technical command and a similar disregard for musical boundaries, is just another step on the journey.

“With Brad and I, it’s interesting how we have covered some of the same artists: he has always checked in on what Radiohead are doing, he’s done Smiths songs, he’s played Bach. If you are a musician of voracious musical appetite, you’re going to seek out the work of great musicians and you’re going to attempt to put yourselves in their shoes, to see through performance what it might have been like to be in their heads when they were creating that music, and doing that in Brad’s company is such a thrill for me. The lucidity of Brad’s improv, his overall sense of musicality, there’s not a musician alive who has fewer obstructions between his mind and his fingertips.”

Thile’s command of the mandolin also puts him in a very elite group of musicians worldwide. Even so, the piano is perhaps not the first instrument you would place alongside his tiny eight-stringed mandolin.

“Yeah, the piano is such a mighty instrument and the mandolin is not, but with a musician of Brad’s sensitivity that’s never an issue. He is so aware of what’s going on, what sound is being made and how he can compliment that.

“I would say that both Brad and I approach our instruments as if they were our speaking voices. And, you know, two people don’t let the potentially odd blend of their speaking voices get in the way of a conversation that they can have, and I do think that our musical vocabularies are very compatible. So when he says something musically, I feel like I understand it, and when I say something, I know he understands it.”

Another thing that Mehldau and Thile share is the prodigy tag. Both rose to fame as comparatively young men, and both have done a lot of their growing up on stage. “We’ve never discussed it, but it’s felt,” says Thile. “I can feel it in his instincts. The idea that it’s easier to make music than not to make music. It’s a joy to be onstage together, night in, night out, just to see what happens.”

Chris Thile and Brad Mehldau are at the National Concert Hall, in Dublin, tomorrow