Crossover duo Hilary Hahn and Josh Ritter make classical rock

In a grainy YouTube video shot from the rear of a music club, Hilary Hahn, the Grammy-winning classical violinist, is in the midst of a rock jam, fiddling furiously as she shares the stage with the Texas band called ...And You Will Know Us by the Trail of Dead. As the song reaches its peak, Hahn, clad in black jeans and T-shirt, moves to center stage and kneels down to strike a classic rocker pose with her electric violin as the crowd cheers.

The moment is uncharacteristic, at least to anyone familiar with the more prim evening-gown images featured on Hahn's album covers and publicity shots. It's also part of a growing series of sideline projects that the 28-year-old violinist has forged with the indie-rock community.

In recent years she has performed alongside singer-songwriters Josh Ritter and Tom Brosseau and been featured in James Newton Howard's folk-inspired soundtrack to the 2004 film "The Village." Hahn believes these projects allow her to keep fresh as a musician, exploring the now-bygone classical musician's art of improvisation while gathering new ideas that she brings back to her classical performances.

"I feel like I learn the most when I go into someone's strength and try to survive in that context," says Hahn, who has been playing with orchestras since she was 12. "That's really when you learn. You learn a lot about yourself as a musician and you learn to think differently as a musician."

A family connection

Next week Hahn and Ritter will embark on a short tour of college towns in Ohio followed by a performance at New York's Metropolitan Museum of Art on April 12. The two musicians met through a family connection – her aunt and his parents are neuroscientists – and Hahn first suggested that they perform together when their individual tours brought them to Montreal in 2005.

"A couple days before my first rehearsal in Montreal I saw that he was going to be playing there," explains Hahn, who had been performing with the Montreal Symphony. The two musicians met for lunch. "I said, 'You know, if you ever need a violinist, I am interested. I don't really do much else besides classical, but I want to do it for the learning experience.' He said, 'Sure, you want to play tomorrow?' "

Hahn accepted and admits that her "knees were shaking" during the entire performance at the Cafe Campus, a downtown rock club. But she was encouraged by the clubgoers' response to her performances of a Bach partita and Schubert's song, "Der Erlkönig," arranged by 19th-century violinist Heinrich Wilhelm Ernst. She and Ritter soon sought other opportunities to perform together and found ways to balance rock showmanship with classical formality.

"One thing that's been important to me in this project is to keep it in classical venues," Hahn says. "Classical music feels it has to go outside of its home to draw people in. But the ideal place for playing classical music is a concert hall – without amplification, with the acoustics that are there, with people comfortably seated."

Ritter, in turn, said he appreciates the attentive audiences and backstage amenities at concert halls. "There were nice boxes of chocolates," he says, surprised.

A program of give and take

Constructing a program was another challenge. Ritter's songs are often densely lyrical. A less sensitive violinist would risk muddling his epic narratives of love, faith, war, and politics. Hahn supplies minimalist, folk-style accompaniments on some of his tunes, while sitting out others. Ritter, meanwhile, worked up a violin-and-guitar version of a Paganini cantabile. "It's taken a lot of practice," he says. "There are chords there I didn't know existed."

Collaborations between classical and nonclassical musicians are nothing new, of course, but lately the trend has shed some of its pops aura. In January, pianist Ethan Iverson of the jazz group The Bad Plus joined tenor Mark Padmore at Carnegie Hall to perform Schubert's song cycle "Winterreise." Last summer, several American orchestras featured the lit-rock band The Decemberists.

Hahn believes that playing indie-rock helps her become more aware of harmonies and structures when she returns to the classical repertoire. Ritter, in turn, finds that Hahn takes him out of his comfort zone: "When I'm playing with my own band, there are moments to be comfortable with a song night to night," he says. "But I also enjoy the uncertainty."