I feel it will always be home to me."Kozena has plans to record a complete anthology of Czech song drawn from several centuries but the problem is deciding what not to include. "It is so difficult for foreigners to sing the Czech language properly and to capture the mood. A disc of a Bach aria with a Czech ensemble happened to catch the ears of the bosses at Deutsche Grammophon and, with almost indecent haste, Kozena's international career was launched.She explains her passion for her native country's music. She was, she recalls, "totally in love with the piano".But an accident at school, resulting in a broken hand, left her suddenly having to audition instead as a singer for the Brno Conservatoire. There, and later in Bratislava, she became captivated by her native music while cultivating an interest in the Baroque repertoire.

It was in this field that she first attracted critical acclaim. An obvious attraction is the chance to attend the Berlin Philharmonic, which she considers a privilege. "Some parts of the city remind me of my own country - if not always pretty, they're at least interesting. The streets are big and wide and you can really breathe."By her "own country" she means, of course, the Czech Republic. And the parts of Berlin that seem familiar to her are not here in West Berlin - where she and Rattle live with their new baby, Jonas, in what one friend describes as "great happiness in a lovely house" - but on the East side. There are certainly parallels between it and the industrial city of Brno where Kozena was born in 1973.

Her father, a mathematician, died when she was 11; her mother, a biologist, brought up Kozena and her sister alone. Kozena's childhood was spent singing, from the age of six, "every day, even weekends" in the Brno Philharmonic Children's Choir Yet it was as a pianist that she planned to make a career. But she's since become very wary of intrusion into her personal life, and our interview is attended by a minder, a director from the London management whose list of artists also includes Rattle, the principal conductor of the Berlin Philharmonic. Kozena loves Berlin, she says, and finds living there exciting. The Czech mezzo-soprano had little option when her appearance at the Proms last year coincided with news of her affair with Sir Simon Rattle, attracting some juicy headlines. It is a mark of her cool professionalism that her impeccable performance of Czech orchestral songs showed no evidence of the hounding she was experiencing in the press. Coldplay's X&Y is set to become one of the fastest-selling albums of all time after hitting the shops yesterday.