Bachmann, who was born in Switzerland in 1944, showed musical talent from an early age and studied at the Lucerne and Berlin Conservatories, soon being accredited by Rafael Kubelik as an outstanding conducting talent. International recognition came early when, aged only 21, he carried off the prestigious Concours de Jeunes Chefs d'Orchestre prize in Besancon. At about the same time he made a decision to compose as well, and still pursues both activities in tandem, in his words "allowing for a profitable and symbiotic relationship, for when one is steeped in a tradition, it is possible in one's own work to continue and question it simultaneously."
So, in his twenties, the enquiring Bachmann headed to Darmstadt. "Stockhausen, Ligeti and others became invaluable friends and profound intellectual influences for me," he reflects, "but soon I also knew I had to forge out on my own. I was associated with the Fluxus group, but the avant-garde musical happening lost its appeal and its cultural place. For me, further learning came through listening and via solitude." He is not overtly prolific as a composer, and is the author of a still- growing number of books on diverse subjects to boot. Bachmann's deeply philosophical engagements with the world gradually led to what is (and, via reworkings, continues to be) his magnum opus, the Uluru Symphony.
So far the Uluru concept has preoccupied him for six years, and still does. An immediate focal point of inspiration was a visit he made to Ayers Rock, but the symphony's intellectual genesis is fractal geometry (and its subtitle - The Fractal Symphony). Bachmann went straight to the heart of the matter, launching into active discussion not only with the deviser of fractal geometry, Benoit Mandelbrot, but also the physicist Gerd Binnig and the mathematician Mitchell Feigenbaum. "How could these important contemporary theories - fractal geometry, catastrophe theory and their offshoots - be applied to music?" he asks. "For some time I didn't know but, visiting Ayers Rock, I found a visual parallel: a huge natural object, itself made up of ever-smaller particles. Seeing a fractal process in action then seemed further to animate the rock, especially when its mystical function in Aboriginal mythology entered the equation."
The ongoing expansion of the Uluru project is, of itself, neatly "fractal", giving rise to a number of versions into which various soloists and other media can be incorporated. Over the coming months Bachmann returns to the studio to produce, with the mezzo-soprano Christina Ascher, Uluru, the vocal version, subtitled Songlines.
And, in fact, it was by the shores of Lake Lucerne that I recently witnessed Uluru's newest incarnation - a recorded airing of the music, which is written for an orchestra of 108, to the accompaniment of a lavish fireworks display. Bachmann talks of working with a Swiss pyrotechnics expert to produce a "fireworks score", which minutely parallels his musical one, and which he hopes can be exported to any interested parties.
"These days, in order to explore new ground the artist also has to be an entrepreneur," he says. Certainly the world premiere of Uluru with fireworks was already a unique experience - a strange mix of Australia and the Alps, with the lake's surrounding high crags allowing for long, resonating echoes from both Uluru's high- energy sound and the detonating fireworks themselves.
In his next visit to the UK to work with the RPO early next March, Bachmann promises "with the aid of complex sound installation, a live airing of a section of Uluru" as a prelude to his account of Bruckner's Fifth Symphony, from which Uluru quotes. In the meantime, next Monday's concert begins with an altogether different-sounding piece - Rotation 90N, a serene and meditative work for low strings, inspired by a visit Bachmann made to the North Pole in 1990.
"Seeking a spot as far removed from civilisation as possible, I set up my tent at the pole in order to experience a sense of elemental solitude," he says. "The music, which is calm and impenetrable, reflects what might be called an interstice of inner peace - this is where latitude 90N intersects with all lines of longitude, and where you actually sit on the axis of the Earth, in the very centre of its vast and powerful locale. This self- lived rotation forms theessence of my composition."
Spirit of place is evidently highly important to him, be it Ayers Rock, the North Pole or the Bruckner shrine of St Florian. Bachmann reflects: "Whenever I am on my way from Lucerne to Vienna or Linz I pay a visit to St Florian, where Bruckner played the organ, and if the organ is being played it is not too difficult for me to imagine it is he who is at the keyboard." A transcendental experience? Yes, but an experience that doesn't stay at that; rather, "it sets up a flow of energy, from the music to the architecture, and back and forward to the reciprocal architecture of Bruckner's vast symphonies. When I conduct a work like the Seventh I hope to guide the orchestra, and so the audience, not only through time but through space, towards the inner self, the core of Bruckner's music, which is love: divine essence."
Mon, 7.30pm (0171-638 8891)