“In my heart, I don’t know that I believe in straight-ahead jazz,” says 22-year-old guitarist Julian Lage while on a lunch break in Boston.

He’s training to become an instructor in the Alexander technique, a practice in alternative medicine used to improve motion, balance, coordination, and poise by changing habits. It’s a new endeavor for a man who, despite his young age, has already led a storied musical career. Though it’s not entirely out of character.

Poise and fluid motion are constant in Lage’s recordings. His sponge-like absorption of disparate influences renders his music both familiar and alien.

“Diversity is what I’m really fascinated by,” he says. His impressive collaborations back the claim. In recent years, he’s worked with a range of pop, rock, jazz, and classical acts like Eric Clapton, Carlos Santana, Béla Fleck, György Ligeti, John Fahey, and Pat Metheny.

Lage’s own music is rife with motifs borrowed from folk songs and classical compositions. He claims a love for the symphonic grandiosity of Beethoven before gushing over Elliot Carter’s atonal compositions.

But in pulling together sounds that span time and geography, Lage doesn’t merely mash musical idioms together; he synthesizes them. “I’m always attracted to stuff that I can’t put my finger on,” he says. So that’s what he creates.

This approach made 2009’s Sounding Point, Lage’s proper debut and to date his only solo album, a critical favorite and Grammy nominee. Reviewing the album, jazz blog 100 Greatest Jazz Albums pointed out, “Noticeably, there is not a single straight jazz line-up on display. The absence of a conventional drum kit leads to an open sound and approach that places the emphasis on free improvisation and highlights Julian Lage’s prodigious technique. It takes great confidence for musicians to open up their playing in this way; it is a high-risk strategy with nowhere to hide. But the results are spectacular, producing jazz of great subtlety, bending the genre, taking in at times bluegrass, straight ahead jazz, Americana, Indian, and classical elements.”

Perhaps it’s a generational effect. Lage calls his a “YouTube generation,” and says he feels an obligation to make connections between the content to which he — and anyone his age — is exposed to. “It’s not the age of get a job and stick with it for 50 years until you retire,” he says. “The world is open to us, and it’s our job to be open to it.”

So, as he’s been doing for 17 years, Lage is “studying the heck out of the guitar.” He delves into lost eras of music; right now, it’s the earliest days of jazz guitar, “when all the guys were switching from tenor banjo to guitar.” The techniques used then, he says, are almost unheard of today. Those players were without precedent; they were free to invent. Lage looks to pick up where they left off.

Prior to this interview, Lage led his band on a retreat to workshop new ideas. Normally, he says, “You enter with this image, and you get your players to fit into it.” Lately, he’s been trying different approaches, trying to let the music direct itself. “It’s a very unstable process,” he says. “And that’s the beauty of it.”

When Lage takes to the stage at Spoleto, he’ll be accompanied by bassist Jorge Roeder. “We don’t often do duo shows,” Lage says, “but it’s often the highlight of our group sets when we split off to the two of us.” Besides, as he says, “If you want diverse music, you have to have diverse processes.”

Indeed, the only constant has been change. It’s been a steady evolution for Lage. He asked for a guitar at age four. “When I was 5, it was all about blues guitar,” he recalls. “I got into jazz when I was about eight.” The oldest of five children, Lage admits he was always looking for something to call his own. Growing up, he tried skateboarding and computer programming, but those interests faded. “Music stayed in my life because it was bigger than me,” he says.