So when Hahn was invited to appear at a concert by the singer-songwriter Josh Ritter, she worked out in advance how she would play along with one of his songs — a time-honored means of “improvisation” for plenty of classical musicians, particularly singers performing Handel operas. But when she came to rehearsal on the day of the show, Hahn discovered that Ritter was playing the song in a different key, and she didn’t have time to transpose what she’d written.
Thus, at the performance, Hahn was flying blind. “I walked on stage with a few ideas and my knees knocking,” she said, speaking by phone from the airport on her way to Japan, “and I played something. I didn’t break the song, and he was happy enough. It was exhilarating,” she laughed, and, for someone who had never improvised, an aha! moment: “Oh, that’s how that’s done.”
Hahn has come a long way with improvisation since. She’s toured with Ritter, appeared with other non-classical artists, and now, on Monday night at the Birchmere, she will show Washington the fruits of her biggest improvisational project yet. A couple of years ago, she was introduced to Hauschka, a German experimental pianist whose inquisitive approach to music seemed in accord with Hahn’s own probing curiosity. Over the next couple of years, they traded sound files and ideas, and they finally went into a recording studio together to see what would happen, thinking maybe they would come up with a track or two. What happened, however, was a whole album, “Silfra,” released in May, which is the basis for Monday’s Birchmere concert.
“I’d improvised along to previously existing structures, such as songs,” Hahn says. “I hadn’t improvised from nothing.” She adds, “It was just fascinating. I didn’t know where to start. You can start on a note, but then what do you do for the next note?” Rather than the classical artist trying to adapt to a non-classical style, both artists worked together “to find something that was our joint musical language,” Hahn says, “to express something that we wanted to play together.” The result certainly doesn’t sound like anything you’ve heard Hahn play before; the violin takes off in swoops and twangs and rasps, a vocabulary beyond what most concertos offer.
As for improvising: “You can just play,” she said. “Pick up the instrument and just play. That is a revelation.”