Four years ago, Texas-born guitarist and string musician Sarah Jarosz was a rookie on the national roots music scene — an Americana teen sensation with a ton of natural singing talent, a penchant for smart songwriting, and great chops on the six-string, mandolin, and banjo. She also had a freshly inked deal with Sugar Hill Records. These days, Jarosz is a 21-year-old performer with a finely tuned technique, a versatile style, and a bright sense of confidence. She’s also a music school kid dedicated to her studies.

In 2010, after touring the country behind a folksy, melodic debut album titled Song Up in Her Head, Jarosz enrolled in Boston’s prestigious New England Conservatory and dived into the academic side of American music. The role switch from full-time performer to full-time student only enhanced her love for musical exploration.

“It’s been really great, and it has affected how I think about music and what I write,” says Jarosz, speaking from Boston last week during one of the few breaks in her summer touring schedule. “I feel like I’ve learned so much about music that I wouldn’t have learned on my own. It’s opened up my ears to different harmonies and things I wouldn’t have gone to before in a songwriting setting. It’s put me out of my comfort zone in terms of what I usually listen to.”

In addition to her other courses at the Conservatory, Jarosz has delved into an array of jazz history classes and improv workshops that cover the works of the great artists of the 20th century.

“I’ve studied about a lot of the jazz artists I already know and loved, but I’ve also done some things like learning the music of Ornette Coleman and Albert Ayler and playing in a free improvisation ensemble,” Jarosz says. “That’s so different from anything I’ve ever done before and will probably ever do in my own music again, but it’s a great thing to do. It can only be a positive thing to absorb all of that. It’s all over the map, and it’ll expand my ear and my mind, in terms of how I think about music.”

While some elements of Western swing, blues, and be-bop sneak into her songs nowadays, Jarosz’s two albums are firmly rooted in traditional bluegrass, country, and folk styles. Her latest collection, Follow Me Down (released by Sugar Hill last May) veered away from the straight-forward instrumentation of Song Up in Her Head and detoured slightly toward Americana-pop and rock territory. While her debut was an earnest solo album with some extra players on hand, Follow Me Down was a grand project in a Nashville studio with an all-star cast of musicians, including Béla Fleck, Jerry Douglas, Edgar Meyer, Viktor Krauss, Dan Tyminski, Shawn Colvin, Vince Gill, and members of the Punch Brothers. The 11-song collection featured some of Jarosz’s strongest originals alongside a few unexpected twists, like renditions of Radiohead’s “The Tourist” and Bob Dylan’s folk hymn “Ring Them Bells.”

“The songs from Follow Me Down have kind of taken on a new life with the trio of me, Alex Hargreaves [violin], and Nathaniel Smith [cello],” Jarosz says. “We wanted to make them sound their best in a trio setting. On the album, there’s more instrumentation involved, and there’s naturally a lot of space in a trio like ours. We’ve worked hard on figuring out how to fill some of the space together. We also want to leave some space, because, in essence, that’s what gives the trio such a cool and unique sound.”

Jarosz made her first trip to Charleston last year during the 2011 Spoleto Festival’s Wells Fargo Jazz series. Follow Me Down had been out for merely a few weeks. She performed for a huge audience with her trio under the oaks at the Cistern. This week, all three bandmates return to town for an indoor performance at the spacious Hippodrome theatre.

“I always tour with Alex and Nat, and only occasionally do we bring on guest musicians,” Jarosz says. “If we’re at a big festival where there are a bunch of other performers, we might bring someone up for a song or two. Otherwise, it’s just us.”

Jarosz’s solo outings have become more frequent this year, too. Earlier this summer, she opened for Vince Gill on a long string of dates. “I like the freedom of doing a show as a solo act,” she says. “I can take more time with it, and the pace is totally up to me. But I also love being driven and pushed by the guys playing with me. There’s a real energy to that.”