Some of the artists in this weekend's String Theory Music Festival occasionally refer to the fest's more distinguished acts as "rock stars." While a chamber-music composer like Missy Mazzoli may never sell out Target Center, the term isn't necessarily off the mark, since she and her cohorts have dipped more than a toe in rock 'n' roll waters.

"It can be horrifying and stressful to approach any genre you have no entryway to, but there's nothing wrong with liking something because you like it," said Brooklyn-based violist Nadia Sirota, who performs on opening night Thursday.

It is this line between accessibility and classical discipline that the Southern Theater is trying to blur with its four-day celebration of string players and composers. The lineup includes violinist and indie-rock darling Owen Pallett, and a new piece by Nico Muhly, who did string and choral arrangements on Grizzly Bear's album "Veckatimest."

"A festival that celebrates strings in classical terms and how they're used in modern music styles was really appealing to us," says Southern music curator Kate Nordstrum.

The weekend boasts substantial premieres and unique collaborations. Pallett will perform new interpretations of his work with Brooklyn's multi-instrumental collective yMusic on Friday show at the History Theatre in St. Paul. Critically hailed New York string ensemble JACK Quartet will make its first visit to the Twin Cities as Sunday's closer.

One of Thursday's opening shows will be the season's final installment of "Southern Songbook." Adam Levy, frontman for the Honeydogs, returns as host with singer/songwriter Chris Koza for an evening of Twin Cities string artistry at the Southern. Doomtree's Dessa will be backed by a string ensemble while composer and ex-new-waver Chan Poling and rootsy rocker Martin Devaney will offer personally orchestrated pieces.

The show's guitars mark a digression from the weekend at large, but Levy and "Southern Songbook" music director Devon Grey (dVRG of Heiruspecs fame) have incorporated their affinity for bowed instruments, be it bass or fiddle.

"There's something very human-sounding about bowed string instruments," Levy said. "Even in an ensemble it brings a mood to it all that an organ or other instruments can't."

Also Thursday, Sirota will meld concert and installation in the Walker Art Center's Gallery 2, performing with Brooklyn keyboardist Missy Mazzoli. Mazzoli's work often includes electronic atmospherics that blur the line between pop and classical. This goes even further with her chamber band Victoire, which performs Sunday at the History Theatre. "When you use weird keyboards, it shifts towards that 'pop' sound, but it's kind of the same for me," Mazzoli said. "My hope is that people are drawn in by something they're familiar with, but then take away something new."

This genre guessing game can be a bit of a distraction. "If you hear Missy's music on the Current [89.3 FM], it's read as one thing, and if you hear it on a classical station it's another," said Sirota.

The two share an interest in seeing music as music. There is an inherently expressive quality to strings, an emotive force that does not demand a scholastic approach.

"I feel like this festival is amazing in that it really takes the best of all possible worlds," Mazzoli said.