It's an intriguing mix of cultural opposites, and one which highlights the contradictions underpinning the current popularity in the classical world of a music which began in the proletarian bars of Buenos Aires amid, as the great Argentinian writer Jorge Luis Borges wrote in his poem "The Tango": "A mythology of knife thrusts/slowly dying in oblivion". A further element is provided by the context for the project, which is an album for the German ECM label, an imprint whose reputation for crystalline purity of sound is perhaps as much of an influence on its recordings as the contributions of the performers themselves. Tango squeezebox meets high-art string quartet in the glacier of an ECM soundscape is quite a combination. To complicate matters even further, the bandoneon actually derives from the Ruhr region of Germany, where it was invented by one Heinrich Band in 1846, and later taken to Argentina by German emigrants.
The way Dino Saluzzi and the Rosamundes talk about Kultrum, their new album of tango variations, speaks volumes. The members of the quartet sit up straight and are punctilious in their attention to questions, while Saluzzi slouches and tends to favour grand Latin shrugs and gestures. The Rosamundes think seriously about music, their non-verbal communication seems to say, but for Saluzzi, it just is.
"It's our responsibility to create, to move, to give life," he says. "It's not technical. The technique is the first point; after this comes the art."
"Dino just plays us what he wants, and we see from his face if what we do is wrong," says Anja Lechner, the quartet's cellist, who has prior experience of tango, having made four albums in the past. It's true that the quartet's English is better than Saluzzi's, but there's still a world of difference between them.
By the age of 14 Saluzzi (who, like much of tango itself, is of Sicilian descent), was already leading his first band, in the Salta province of Northern Argentina where he grew up. After studying in Buenos Aires he assisted his friend, the late, great composer Astor Piazzola in the formation of "Tango Nuevo', and also played in the group of the jazz saxophonist Gato Barbieri.
Later, as an exile in Europe, Saluzzi recorded for ECM with jazz musicians such as Charlie Haden and Don Cherry, pioneering a superior kind of "world music" mixing disparate folk forms with jazz. It was at a tango concert in Munich in 1984 that Anja Lechner saw Saluzzi play for the first time and decided that she would love to work with him one day, although the prospect seemed unlikely.
Happily, the album Saluzzi and the quartet have made together adds up to more than just the sum of their parts. Instead, a strange sort of cross- cultural transference appears to have taken place. As the series of variations unwinds, the strings sound more and more impassioned, while the composer himself is uncharacteristically restrained until space is cleared for the improvised cadenzas which are neatly woven into each piece. Here, Saluzzi is suddenly set free, and the sounds of his instrument - which are incredibly diverse, at times suggesting a clarinet, or seeming to duplicate the violin, viola or cello of the quartet - soar into flight.
It is a process which is reinforced when the musicians perform in the church of the monastery of St Gerold's in the foothills of the Austrian Tyrol, where the album was recorded earlier this year. This is no ordinary venue: it is where Jan Garbarek and the Hilliard Ensemble's ECM album Officium - which has sold 850,000 copies to date - was recorded in 1994, and in the spacious acoustic of the building Saluzzi's music really comes alive. It may be a long way from the bars of Buenos Aires, but the woody bloom of the strings fills the church and mixes most effectively with the breathy timbres of the bandoneon, whose wheezing between notes can be heard in the quietest moments . Unlike most other "fusion" projects, this one actually works as music rather than marketing.
"I hate fusion and this crossover nonsense," says Manfred Eicher of ECM, who has produced every release on the label since its formation in 1969. "There has always been cultural interaction between different styles, and these terms don't mean anything to me. We have chosen a string quartet, but it's not a fusion; it's coming out of Dino Saluzzi's own ideas and his previous solo work. It comes from the same genre, the same creator."
The idea of a specific ECM sound or aesthetic is something that Eicher dismisses: "People often talk in cliches. What I think the ECM sound is, is more to do with the choice of musicians in the catalogue. It also has had a lot to do with my love of chamber music, and a poetic approach to music. My preference is towards music which has to do with transparency, with the movements of sound, but also with pauses and silence. It's not only the notes, but the thought behind them that sculpts sound, transforming what we hear in a church into a manifestation for the listener, who hopefully trusts this result of musicians, sound engineer and producer, since everyone listens to music with their own ears."
More likely to quote Goethe than to discuss the positioning of microphones, Eicher makes mysticism seem almost mundane. "It's the white space, the empty space between the tones, that's the inspirational source," he says, before going off to rehearse the musicians for their performance.
At the press conference, Saluzzi is growing more animated by the minute. "We have to be true to the idea of the simple people," he says in answer to a question about the album's mix of cultures. "Why make our territorial claim against someone else? We have to wake up to the human being more, to remain true to our dreams and our utopias, for our job is nothing if it is only for us."
The members of the quartet nod seriously in agreement, although, in truth, it is not easy to see what Saluzzi is on about. That morning, as the sun suddenly comes out and lights up the snowcapped mountains in a manner reminiscent of Caspar David Friedrich - a stunning manifestation of the ECM aesthetic that is supposed not to exist - Manfred Eicher dispatches a photographer to record the moment. Some day it might appear as an ECM cover.
`Kultrum' by Dino Saluzzi and the Rosamunde String Quartet is out now on ECM