Galway's resident Romanian string quartet, made up of two married couples, begin their series of summer concerts this week. The members of the ConTempo Quartet like to joke about the fact that they are unique in the world of string quartets. They talk to Michael Dervan.

They are not just two couples, they are two married couples. They introduce themselves to their audiences by explaining: "We're the Abba among string quartets."

It's the cellist, Adrian Mantu, who does most of the talking. He's the quartet's voluble salesman, spotting the angles and the openings, his concern with spin usually masked by his openness and enthusiasm. The leader, Bogdan Sofei, is altogether quieter, not only saying less but mostly seeming to weigh his words much more carefully.

Second violinist Ingrid Nicola is the bubblier of the two women. Her whole being can light up with animation when she speaks. Viola player Andreea Banciu talks rather more, and likes to get the bit between her teeth in an issue-driven way.

The word "fight" comes into their conversation a lot when they talk about their working methods. They have Latin blood, they explain. They like to push things out into the open. They have, it seems, rather shocked some of their mentors when being tutored, and pleasantly surprised them at subsequent concerts. The rough and tumble is for the rehearsal room. The performance requires a flexible unity of purpose. And they've come up with a novel way of handling rehearsals. They rotate the leadership, the role of one who must be obeyed, on a daily basis. That way everyone has the opportunity, whatever the democratic split, to insist on his or her ideas being tried out.

The players, who are celebrating their 10th anniversary as a quartet this year, met while students at the music university in Bucharest. They had all studied in Romania's special music schools from childhood, but their initial career expectations varied wildly. Mantu, for instance, was aiming for a career as a solo cellist. Banciu had a childhood love affair with the orchestra, from going to weekly concerts at the Athenaeum in Bucharest. She was forced by an ambitious father ("severe" is the word she uses) from violin to viola in an effort to get her to the top of the class - she was tall for her age, a big advantage on the viola.

Nicola, on the other hand, knew that the constraints of orchestral life would never have worked for her. Her experience of orchestras was that they were "very messy"; perhaps, she explains, because the ones she played in weren't that good. But her feeling remains that "you lose your own personality playing in an orchestra". Sofei says: "I just wanted to study music and to go as far as possible. I didn't know where that would lead."

Not long after they became a quartet, they entered their first international competition, the Valentino Bucchi International Competition in Rome. They had obviously clicked as an ensemble. They won a prize and used some of the money to buy better bows, the rest to fund a trip to another competition.

They took to the competition circuit with such enthusiasm that it almost became a way of life, bringing them a total of 13 prizes. They used the money as a way of keeping themselves on the road.

It was tough in ways you might not immediately suspect. They were living in Romania and they needed visas to travel around Europe. And as they were hard up, they travelled overland when it was cheaper than flying, which meant a separate visa for each country of transit.

"After one trip to Spain, the passport was already full of visas," says Mantu. And getting those visas involved endless amounts of red tape.

Given that none of them had actually started out with an ambition to be a quartet member, I asked them about the specific rewards of working in a quartet. For Mantu, "it's like a drug. If you take it once you can't escape." When he played in orchestras he used to fight with the conductors.

"It was a nightmare for them, and they were for me, as well," he says. In a string quartet, he adds, "you are a conductor, you are a musician, you are a composer, you are a musicologist. It is perfect. If you can play well enough in a string quartet, you can be a very good soloist, or a very good orchestra player, or a very good conductor." But quartet playing, he insists, is also a tough calling.

"There are four people," he says. "You have to take their responsibilities, they have to take your responsibilities. It's very challenging, it's very equal, it's very democratic. Life in a string quartet is not easy. You live together, like in a marriage, four people from morning until evening, thinking, living, breathing quartets, doing things together. You need 10 lives to play all the repertoire."

"Playing in a string quartet is intellectually demanding, so I like this," says Banciu. "You don't expect someone to come and say 'do this!' and you just obey, like in an orchestra. It's nice to use your brain and find the ideas on your own. The repertoire, as well, is so vast. Being together is very nice. In an orchestra, it's very difficult to make friendships, it's too big. And as a soloist you are always alone. This is like having your family with you all the time."

Nicola opens with an unexpected declaration. "My favourite instrument is the organ," she says. "Because, I don't know, it can give you thrills. Every time I listen to the organ I feel I am closer to God. It's so powerful for me. Choral music is very powerful, too. And also the string quartet, because the string quartet can imitate so well the organ sonority, the orchestra and the voice. You can do so many colours, it's almost perfect."

Sofei is the one member who has no hang-ups about playing in an orchestra, though obviously, he points out, the rewards would depend on the other members of the orchestra as well as on the conductors. He was motivated early on by the tonal possibilities of the quartet, particularly as he came to know them through the work of the Romanian ensemble, the Voces Quartet. Simply put, he would like to play in a quartet that could equal their achievements.

In the early days, the ConTempos were innocents. They simply didn't think about the difficulties. They did the preparation, they played, and it went down well. They fell in love with playing string quartets. When the initial glow faded, when they had gone as far as their instincts could take them, "then it was very tough", says Banciu. There were external factors. They became aware of the quality of the competition they faced. And, internally, "we fought about musical ideas. We are very impulsive. We couldn't control ourselves. We always say what we think. It's very honest, it's very good. But we had to learn to know how to say things to each other."

"As a string quartet," says Nicola, "you have to be like a chameleon. You have to try to believe in the others as much as you believe in yourself. You really have to lose yourself and be with the other three. You have to try to be as generous as possible. It took time for me to understand this. I didn't get it from the beginning. And even when you understand it, it's very difficult to do it."

On one thing, they are completely united, the group they single out as the ensemble they admire most: the Hagen Quartet. The explanation is that they like the way the Hagens place the composer first, putting themselves as players second, and yet they experiment a lot and are very original. There's also a novelty of sound, which, they feel, somehow transcends the norms of the quartet world.

A quartet with two couples inevitably has an internal dynamic different from other quartets - but in what way, exactly, the ConTempos can't tell. They were couples from the start, with the split going right down the middle, violin married to violin, viola to cello.

They present themselves as passionate and temperamental people, striving to be as open as possible in their work and as embracing as they possibly can be of new ideas. Two commentsseem to sum them up. Viola player Banciu says of working as couples: "When you play with your partner, it's like opening your soul completely." Second violinist Nicola says: "If you don't experiment in your playing, you die. You have to. It's a must."

The ConTempo Quartet's concert series at Galway Arts Festival runs from tomorrow until Saturday, with guests Bruno Giuranna (viola), Martin Lovett (cello), Lory Wallfisch (piano), Emma Johnson (clarinet), Hugh Tinney (piano), Máirtín O'Connor (box), Gary Ó Briain (mandocello) and Cathal Hayden (fiddle). Details: 091-566577