Mark O'Connor is on the phone from New York, explaining why he had to make a change in his schedule.
"I came in a day early and went to Isaac Stern's birthday party," he says. "Lot of good music, friends. Yo-Yo played, Manny Ax, Midori, Zukerman. It was good."
To some music fans, it may seem odd that O'Connor would be on such intimate terms with classical musicians. Sure, he's made a few genre-jumping albums with Yo-Yo Ma, "Appalachian Journey" being the most recent. But Isaac Stern? Pinchas Zukerman? Emmanuel Ax? That seems pretty high-toned company for a Nashville fiddler.
Except that O'Connor isn't a Nashville fiddler; he's a violinist and composer who has written and recorded several works for violin and orchestra. Tonight, he'll join violinist Nadja Salerno-Sonnenberg for the Baltimore Symphony Opera performance of his brand-new double concerto for violin.
Naturally, O'Connor understands how people might have the wrong idea. After all, he was a big name in Nashville, playing on hundreds of recordings and winning countless country music awards.
But Nashville was only one stop on his career itinerary and hardly the longest one.
"I spent six years as a session musician and now about 10 years playing my concertos and doing recitals with my new music," he says. These days, his recording contract, his performance schedule, even his friendships are focused on classical music.
Even so, O'Connor does not take quite the same approach to symphonic music as his conservatory-trained peers. His roots are in American idioms, and pieces like his "Fiddle Concerto" or the tunes on "Appalachia Waltz" reflect his affinity for country and folk music.
"This concerto is a musical departure for me," he says of the new work. "My first two concertos use a lot of inspiration from the American folk music world and the Celtic folk music world. This one features mostly jazz and blues influence."
Jazz and blues are by no means a stretch for O'Connor. He studied with jazz great Stephane Grappelli and was for a time a member of the jazz fusion band the Dixie Dregs. But it would be hard to name too many other virtuoso violinists who would be equally at home with those styles. And without a second soloist, how could O'Connor have a double concerto?
Fortunately, he had the perfect player in mind: Salerno-Sonnenberg.
Although Salerno-Sonnenberg is well-versed in traditional concerto fare - she'll perform the Tchaikovsky concerto with the BSO as well as the O'Connor - she has also tried her hand at other styles, recording both the jazz-oriented album "Humoresque" as well as a collection of pieces influenced by Arab, Gypsy and flamenco music with guitarists Sergio and Odair Assad.
"She's perfect for this," says O'Connor. "Her 'Humoresque' album had, I think, the most contemporary and cool-sounding phrasing of any modern-day violinist. So that was my hope that Nadja would like the concerto."
O'Connor approached Salerno-Sonnenberg in Chicago, where she was performing with the Chicago Symphony Orchestra.
"I had been a fan for a while and had no idea he was there," she says. "He said, 'I'm thinking about writing a double violin concerto. What do you think about playing it?' And my first instinct was to say, 'Yes!'
"But then, so many people say things. You know, 'Call me, we'll have lunch.' So we chatted, and that was the end of that. Then, very shortly after that, I got a fully printed package, with the two violin parts and the score. Boom! It was done."
Writing a jazz-oriented piece for symphony players is no easy task. O'Connor mentions other composers' attempts at symphonic swing and seems to shudder, saying that most such works "have not been homeruns for me." What bothers him isn't that these pieces aren't sufficiently jazzy; it's that they don't make sufficient use of the orchestra.
"It really has to become something else when you involve an orchestra," he says. "Or why are you involving this whole body of musicians who might as well be playing Mahler?"
To that end, O'Connor has written a piece that demands as much of the orchestra as it does of the soloists. "It's almost as if the writing in this piece is linear, rather than vertical," he says, meaning that instead of large, block chords, the sections of the orchestra often play intricate, interlocking lines, making the harmonies seem less like chords than a collision of melodies.
"What seem to be, on the outside, fairly catchy melodic lines, once brought together actually become fairly dissonant," he says. Imagine a cross between Bartok, Milhaud and a Creole jazz band, and you'll have some sense of how the pieces fit together.
Of course, what would a jazz-oriented piece be without improvisation? But while O'Connor sometimes takes solos in the jazz sense, every note Salerno-Sonnenberg plays is written out in the classical tradition, and that can make for some very interesting onstage dynamics.
"The idea for his concerto is that these two worlds come together by the end of the piece," Salerno-Sonnenberg says. "But I don't want it to take that long." She laughs and adds that the cadenza section in the first movement gives her an early opportunity to make the leap from classical to jazz.
It's presented as a dialogue between the two soloists, with O'Connor and Salerno-Sonnenberg trading increasingly shorter phrases until they end up in an actual duet. The thing is, O'Connor is improvising the whole time.
"My part is very classical, very Paganini-like," she says. "And he's just doing what he wants to do, whatever he feels like that night. Then he writes more jazz licks for me, and it becomes more of a unison. By the end of the cadenza, it's foot-stomping time.
"I think that's the point of the work, entirely," she adds, a big smile on her face.
What: Mark O'Connor and Nadja Salerno-Sonnenberg with the Baltimore Symphony
When: Tonight and Thursday, 8 p.m.
Where: Meyerhoff Symphony Hall, 1212 Cathedral St.
Tickets: $30 - $88.