Laura Gibson and Ethan Rose's new collaboration began with an experiment that could have come from any entry-level creative-writing class.

"I would write words down on a piece of paper and then say them to Laura, and she would sing as long as she wanted to on that word," Rose says, huddling around a space heater in the basement of his North Portland home. "When she ran out of ideas, I'd go to the next one."

Singer-songwriter Gibson and sound architect Rose knew they wanted to work together since first meeting four years ago, but only if they approached it as an art project separate from their normal lines of work. So, instead of writing formal songs, their new record, Bridge Carols, was pieced together during most of 2008 from fragments and fleeting moments based around improvisation and spontaneity.

The first song they completed, "Younger," came from a decision to ditch the cold environment of the studio and head outdoors. When the weather was nice in the summer, the two friends would venture to Sauvie Island or Forest Park with a mini recorder and microphone, then hold free-association exercises in the grass. Rose fed random words to Gibson ("mosquito," "sunlight" or ideas from a PBS documentary on scientist Nikola Tesla) and then let the tape roll. For the reserved Gibson, singing off the top of her head was an uncomfortable exercise, and one that forced her to ditch her usual tendency to overthink every little meter and cadence.

"I've always been very specific with my words, and very protective of them and aware of these little things that no one notices in the symmetry of phrases," Gibson says. "So to just sing freely and let it go was a really good exercise for me. That freedom opened me up to the possibilities of words and imagery."

Rose's music, until this point, has been mostly wordless, steeped in the ideas of minimalism and musique concrète: His last record, 2009's Oaks, was made on the old Wurlitzer organ at the Oaks Park Roller Rink. Gibson has increasingly expanded past the confines of finger-picked guitar and verse-chorus song structures, including the use of swirling feedback and a cappella loops on her most recent work, Beasts of Seasons. But Bridge Carols pushes both artists out of their comfort zones, creating an absolutely gorgeous, weightless collection of inviting songs constructed around Gibson's voice.

In fact, many of the sounds on the album—often stretched out and elongated past the point of recognition—are built from recordings of Gibson breathing. Rose treats Gibson's voice as an extra instrument. His role on Bridge Carols is more editor than producer—after each session, Rose would go back and edit the 30-minute chunks, looking for melodic fragments and creating narratives by juxtaposing things she sang. On standout "Younger," the chords and background music are made from loops of Gibson's breath, something that in the past would be the first thing cut from the mix.

"So much of it is reduction—pulling things out, shifting things around," Rose says. "I didn't have the choice of the words, but I could move them about and change the meaning. Laura had the choice, but she didn't really have the full control of arranging them. It ended up being a shared experience, which is neat." That collaboration will continue for live performances, where the artists will trade off instruments and string together a set with just two or three breaks.

The only artistic compromise Rose and Gibson made with Bridge Carols was agreeing to do a radio edit for "Younger," removing the uncouth use of "goddamn" for the FCC.

"There's certain things that I found myself singing that on paper wouldn't make sense to me," Gibson says. "Goddamn" isn't a word she'd normally use in her own work.

Rose chimes in with a different take. "There's going to be a lot of 'motherfuckers' on the next record."

SEE IT:

Laura Gibson and Ethan Rose play Friday, Feb. 12, at Holocene with Benoit Pioulard. 7 pm. $8. 21+.