Nicholas Milton has been busy since taking on his second job in Germany, where he heads the State Opera House in Saarbrücken. On his return to Canberra to conduct the Canberra Symphony Orchestra's next performance, he brings with him two friends from Germany: husband and wife performers violinist Indira Koch and cellist Wolfgang Emanuel Schmidt.

The Llewellyn Series program, 03 Dvorak, begins with Weber's Overture – Der Freischutz and finishing with Dvorak's Symphony No. 7 in D minor. Koch and Schmidt will be soloists in the program's third work: Brahms' Double Concerto for Violin and Cello in A minor.

Schmidt says the couple have long been familiar with Milton's work, and have several concerts with him.

"I love his artistry and his way of approaching music," he says.

The couple are making their first visit to Australia, combining music and holiday in the company of their four children, aged five to 12, and all of whom have, unsurprisingly, a musical bent.

"I'll be playing the Mozart Divertimento in E flat major, Brahms and Mahler piano quartets and an interesting piece by Paul Stanhope for piano trio and voice," Koch says, "and Wolfgang and I will play some duo pieces. Wolfgang will play Schubert's Trout."

Schmidt reveres the Russian cellist Mstislav Rostropovich with whom he worked for three years. "When I was seven I heard him playing the Haydn C major and I was so impressed that I went backstage and wanted his autograph," he says.

"He touched my head and said, 'You are going to be a great cellist.' I didn't want to wash my hair any more and my parents cut off the hair after a week and I actually still have it at home. It was years later that I won his competition and he offered to let me study with him. That was, of course, the chance of my life."

He says he has a penchant for both romantic and modern repertoires.

"As I am also a conductor I love the orchestra repertoire too and then as a chamber musician I'm very flexible," he says.

"The American composer Edgar Meyer wrote a double concerto for double bass and cello which is a little bit jazzy, and he recorded it with Yo-Yo Ma. I was introduced to Meyer and he liked my playing and asked if I'd like to play his concerto with him. It was really cool, but generally I don't play jazz or improvise."

Schmidt plays a Matteo Goffriller cello which previously belonged to Hugo Becker.

"It once belonged to the British cellist Beatrice Harrison who gave first performances of several important English works, especially those of Frederick Delius, and she also premiered the Elgar cello concerto, so my instrument has a nice history."

Koch plays a Guadagnini violin which was made in 1751.

"I'm totally in love with it," she says. "I found my violin in Munich. I didn't even try it out in a concert hall; I just played it and it's been mine for 20 years now. I'm very lucky. I take it everywhere with me. It doesn't react to weather conditions; even when I took it to India. I've never even changed its bridge."

Is the work that they will perform together at this concert, the Brahms Double Concerto, the ideal work for a husband and wife to perform together?

Koch laughs and calls for her husband's opinion.

"In a way, yes," she says. "We just love performing together. And we feel very comfortable with this piece. It's very romantic. We're quite direct with one another."

And there seems to be an intuitive element; she explains that as they were rehearsing a little while ago, they both just opened the music at the same place without conferring.

"When we played in New York 10 years ago my sister was in the audience and she heard a lot of people around her saying, 'Oh, do you think they are married? They keep looking at each other. They must be together.' "

Schmidt says, "Well, the violin is feminine. The German words are violine or geige and the word for cello is neuter, but I think a cello is definitely masculine. Brahms wanted to write a piece for a big violin – one with a large range from base to top – but such an instrument doesn't exist so he chose to divide the parts for two instruments. So, as a couple, I would say that we are one instrument."

Schmidt explains that as a cellist his favourite concertos are by Schumann, Elgar and Shostakovich. "Dvorak as well, of course, the greatest cello concerto ever written but it's not as personal for me as Schumann and Elgar."

Given the chance, what would he most like to play, where, and with which conductor?

Without a moment's hesitation and with consummate diplomacy he replies: "Of course, the Brahms Double with Nick Milton and my wife in Canberra."