“I don’t think you’ll find a name for what we do,” says cellist Anja Lechner of the Saluzzi and Lechner Duo, speaking from her home in Munich.

Lechner and her musical partner Dino Saluzzi celebrated the release of a debut album titled Ojos Negros [“Black Eyes”] with concerts in Argentina and North America this spring. They return to the U.S. this week for an anticipated performance at the Sottile Theatre on Monday evening.

Initially trained as a classical musician, Lechner’s interest in Argentinian folk music and tango goes back some 25 years, when she formed a duo with pianist Peter Ludwig. It wasn’t until she started collaborating with Argentine bandoneón player Saluzzi — as a duo and with the German-based Rosamunde Quartet — that she completely dedicated her efforts into creating a new sound and style from the traditional music.

“I’ve been very interested in playing improvised music since I was 16,” says Lechner. “It’s always been a great wish for me to play with Saluzzi because of his sound and his way of improvising on the bandoneón. I’ve been very much into Argentinian and tango music for years. Although much of what we do comes from the tango and folk music, what we do is something different. It wouldn’t work at all if I was just a normal classical musician who didn’t learn about the culture of Argentina.”

Well known for his compositions and musical agility, Saluzzi stands as an inspired master of his unusual instrument (the bandoneón is basically an accordion with buttons instead of piano-type keys). His collaborative work with Lechner led to the recording and release of Ojos Negros, which bounces delicately with interplay and improvisation between the two players.

Speaking by telephone from a “fantastic morning in Buenos Aires,” Saluzzi describes his experience with the bandoneón and his musical colleagues philosophically:

“With all the things coming to us, we actually come to them,” he says. “It’s part of a destiny where we are open to receive everything. All these things meet and influence our lives. Many instruments are not what they call ‘official instruments’ of the symphony orchestra. All these kinds of instruments are in our future because we have to follow another kind of sound. This instrument is unbelievable. It’s a little bit difficult to make a tune, maybe, but we have a fantastic time. I like the idea of going ahead within classical music.”

The duo’s ambitious approach pushes the boundaries toward a form that has more room to be dynamic. A balance between texture, structure, and interplay propels much of the album. Playing off of each other and improvising is still a vital part of concert music, despite what modern audiences may think. It’s not so structured and stiff.

“People don’t remember that, sometimes,” says Lechner. “But many musicians — in America especially — have played in different settings and have been much more open to new kinds of music than what I know of in Germany. While most of the pieces are composed, so to say, there’s a lot of freedom and a lot of possibilities to improvise or just leave the sheet music and go somewhere else. That happens in concerts quite often. I can follow him, and, if I offer something, he can follow me, like a dialogue between two people.”

“I have a great hope about it,” adds Saluzzi. “The bandoneón works very well with the cello’s range. To open a space to find the place where more beautiful sounds are coming … looking for the range of the instruments to come together. That’s what we try to find. The different colors of music coming together — it means we have a great possibility in the future. Things coming together without losing their personalities.”

DINO SALUZZI & ANJA LECHNER • Spoleto Festival USA’s Wachovia Jazz Series • $10-$40 • (1 hour 15 min.) • May 28 at 5 p.m. • Sottile Theatre, 44 George St. • 579-3100