Ariel Barnes and Heidi Krutzen’s new duo, Couloir, is the most natural development in the world. And it’s also a rather odd thing, when you come to think of it—but we’ll think of that later.

“Ari and I are good friends, and we both approach music in a very similar respect,” Krutzen tells the Straight from her Vancouver home, where she and Barnes have just finished a four-hour rehearsal. “We come from the same place: we’re very interested in our connection to the music and to the audience, in the spiritual nature of music, the depth in music, and sort of getting beyond the notes. So we wanted to see what it would be like to create music together.”

On the other line, Barnes picks up the thread. “We’ve also both had wonderful experiences working with living composers and creating modern music,” he adds. “So we’re interested in developing some relevant contemporary art music that is, perhaps, more engaged in emotional and spiritual approaches than intellectual approaches—which is not to necessarily separate the two or ostracize one from the other.”

The two musicians have already shared some scintillating on-stage moments as members of the Vancouver Opera Orchestra, the Turning Point Ensemble, and a host of other, smaller chamber-music groups. In fact, they’ve known each other for almost all of their professional lives. But there was one small impediment to getting Couloir up and running: they didn’t have anything to play.

“We started getting all these concert opportunities, and we were like, ‘Oh, we have no music!’” Krutzen says, laughing. “It’s usually the other way around: you know what you want to play, so you decide to do some concerts.”

The problem is that Krutzen plays harp, while Barnes is a cellist. Only a handful of composers have ever written for this particular instrumental combination, and for good reason: counting Couloir, says Krutzen, there may be only three professional harp-and-cello duos in the world.

It was immediately obvious that the new group would have to commission some even newer material, and the first of its purpose-made pieces can be heard when Couloir makes its debut at the second annual Modulus Festival. Devoted to the more audience-friendly end of contemporary art music and curated by Music on Main’s insightful David Pay, the event takes place at Heritage Hall on Friday and Saturday (September 30 and October 1). At it, Barnes and Krutzen will premiere Vancouver composer Jocelyn Morlock’s Three Meditations on Light, while contributions from Winnipeg’s Glenn Buhr and his American counterpart Baljinder Sekhon will be ready for the duo’s second hometown appearance, scheduled for December.

Morlock, whose writing is both accessible and rather beautifully eccentric, admits she had mixed feelings when first contacted to write for the group.

“I thought ‘Oh, good! I love writing for Heidi, and for Ari,’” she says, in a separate telephone conversation from her home. “And then I thought ‘Oh, strange! I’ve never heard music for harp and cello before.’ So that was a bit puzzling, but I actually really like the combination.”

Both harp and cello have a huge range, she explains, but composers rarely exploit the cello’s higher register, or the lower notes on the harp. So trying to find new ways of using each instrument was on Morlock’s agenda, but from her description Three Meditations on Light is far more than an exploration of sound. The first movement, “The Birds Breathe the Morning Light”, takes its cue from the dawn chorus familiar to all early risers. “It’s hard for me to avoid birdlike sounds, because I like them so much,” Morlock says. “I try not to, and then I come back to them. I can’t help it.”

The second movement, “Bioluminescence”, was also inspired by the natural world, while the third, “The Absence of Light”, draws on mythic sources.

“I thought of calling it ‘Sol Invictus’ for a while, which means ‘unconquerable sun’, because I’d read this idea which really appealed to me, which was that in far earlier times, they didn’t really know what the sun was, or what was going on with it,” the composer explains. “They imagined that it was on this heroic journey, and that every night it had to do battle in order to come back up. And I love the idea that sunrise is not a given—that the new day is sort of miraculous, even though we take it for granted.”

Although Morlock describes herself, rather diplomatically, as “not your typical religious person”, there is a spiritual dimension to Three Meditations on Light that should satisfy Couloir’s interest in music that has a transcendental dimension. This is also true of the other pieces on the duo’s Modulus Festival program, Nico Muhly’s Clear Music, based on a passage from a John Taverner choral score, and Ukrainian composer Valeri Kikta’s Sonata for Cello and Harp, which incorporates a Russian folk melody.

“When we talk about a spiritual connection to music, it’s sort of like delving behind the confines or constructs of each cultural or religious background, and trying to find out what it is that speaks to people in music, and where it takes them—and I think this is no new question,” says Barnes. “We’re not reinventing the wheel, but we just want to focus more on what that is.”

Couloir plays Heritage Hall on Saturday (October 1), and a noonhour concert at UBC’s Roy Barnett Hall on Wednesday (October 5).