Blurred Music, a live music piece by Biliana Voutchkova and Michael Thieke that features the European musicians improvising along to an improvisation (not a typo; you’ll see), was constructed out of an unexpected surprise.

In 2013, the Berlin-based artists, who had been developing duo material over the previous three years, tackled a creative-music concept they call “blurriness” during a residency near the Baltic Sea. At the time, the music was augmented with dancers.

“The project had been interesting, but regarding the music, we didn't find a satisfying solution to translate the more visual concept into sound,” says Voutchkova, who splits her time between Germany and Bulgaria.

One day, as the two listened back to one of their recordings, one of the tracks went out of sync with the other track, which, Voutchkova remembers, “led to a fascinating sound result.”

“We started to research our recordings for interesting textures, transcribed them and started to construct pieces that included improvised parts with moments of playing back our own recordings while doubling them by playing the same material live,” says Voutchkova about what became Blurred Music.

When it’s performed live, the duo chooses a growing archive of pre-recorded pieces, which the musicians have transcribed. As the recording plays back through a P.A., Voutchkova plays the violin and does voice work while Thieke delivers long tones and sputters out of the clarinet — all in sync with the recording.

It’s sometimes difficult to tell if the sounds are coming from the onstage instruments or the recording. That’s the point.

“The one thing that first comes to mind,” says Voutchkova when asked what specific improvisational techniques she’s developed with Thieke, “is the blending of our sounds, creating one sonorous texture and allowing the time for long progressions of the material until it naturally develops into a new texture. We find new blends of material between the two instruments that complement each other, which is unique for the duo.”

For the group's Nameless Sound concert, the duo – which has one record to their credit, entitled Already There, released in 2013 on the Swiss label Flexion Records – will perform a free improvisation before delivering another installment of Blurred Music.

Biliana Voutchkova and Michael Thieke are scheduled to perform at 8 p.m. Friday, December 9, at 14 Pews, 800 Aurora Street. Tickets cost $10 to $13. For more information, call 713-928-5653 or check out namelesssound.org.