Can music save lives?

The conductor Franz Welser-Möst is due to have a brain scan next month. Nothing wrong with him, he hastens to assure me. Just a bunch of pioneering neuroscientists in Cleveland who are dying to get a look inside the skull of their town orchestra's music director.

"Think about it," he reflects. "What we do as conductors is unique in terms of brain function. We co-ordinate a large group of people but always have to be ahead of the sound. Which part of the brain does that? And, when we find it, how can we apply it to the benefit of medical science?"

For the whole day before his effervescent, high-risk performance of Dvorak's rarely staged Rusalka at the Salzburg Festival this weekend, Welser-Möst, 48, co-chaired an international conference on music and the brain with his new best friend, Ali Rezai, director of the Cleveland Clinic for Neurological Restoration.

Rezai, 43, is an Iranian-born Barack Obama lookalike in a shining white shirt who ranks as a world leader in planting "pacemakers" in the brain. This entails inserting a wire to re-stimulate areas that have been blocked by injury, accident or Parkinson's disease. Since he started going to symphony concerts, Rezai has taken to playing music to his fully conscious patients to see what effect it might have on the brain sections he has exposed. he also does implants on people with severe depression and obsessive-compulsive disorder who are beyond the reach of other therapies.

"I listen to the music of the brain," he tells me with a winning smile. "There's a steady buzz when it's functioning normally, an angry, chaotic sound when there is damage. Therapeutically, we are skimming the surface in how music can promote recovery. There is a connection between music and the mood centres of the brain. It needs to be researched aggressively. This is going to be a vital field."

Sitting through the scientific conference, it was impossible to be unaware of how little we know about the brain, how uncharted is the body organ that Welser-Möst describes as "the conductor of all of our lives" and Rezai refers to as "the missing conductor" in patients who are unable to lift a glass to their mouth because the central nervous system is damaged. Speaker after Nobel-calibre speaker confirmed that, while most of our knowledge is anecdotal, music evidently plays a powerful and mysterious role in the way we function, both normally and abnormally.

A neurologist from hanover reported marked differences in his daughter's heart rate after she played the piano for 20 minutes. A cognitive neuroscientist from Montreal found that music gave more pleasure to his students than any other stimulus except romance (women), sex (men) and sunshine (he's Canadian). Professor Michael Trimble, a behaviourist at the Institute of Neurology in London, suggested that the primal origin of music was funereal keening for the dead, and that the art may have a role to play in how we cope with tragedy and loss.

The most startling piece of new research came from Cleveland's antiageing expert Michael Roizen, a regular on Oprah Winfrey, who claimed that going to concerts can add four years to your life expectancy, eight if you've undergone major surgery. how? And why? This, like many other assertions, sounded like wishful thinking hinged on a small statistical sampling. Much of what we heard struck me as science fiction crossed with faith healing and there were no ultimate conclusions other than a decision by the scientists to confer by email, select the one field where music might have the greatest benefits to medicine and then blitz it with research.

"We have bits and pieces of observation," confirms Rezai, "but in the next decade we will learn enormous amounts. If we can understand how music affects the brain of a healthy musician like Franz, we'll know better how to treat disease."

"What Ali and I want," says Franz, "is to see in effect which parts of us get connected by music and how we can use that knowledge for universal benefit."

Setting aside the mildly alarming Frankenstein aspect of some of these ambitions, I did come away feeling that they could be onto something. Most previous encounters between music and medicine have been dilettanteish on the musical side. herbert von Karajan set up a Foundation for experimental Psychology in Music at the University of Salzburg that has yielded no huge revelations, while Giuseppe Sinopoli, a medical doctor before he took up conducting, spouted no end of psychobabble about the symphonies of Schumann and Mahler, his favourite composers.

Welser-Möst, though, is made of different stuff. The son, grandson and sibling of hospital doctors, he has an appropriately humble approach to the human limitations of medical science. having suffered damage to his nervous system in a car crash at 18, losing the feeling in two fingers, he began reading intensively about the brain. As music director in London and Zurich, he became aware of a rising curve of musical injuries - ear damage, hand problems, stress-related disorders. In Cleveland, where the orchestra and the clinic are the only world beaters in a city of few distractions, he gravitated naturally to a community that strove for the same degree of achievement that he produced in the orchestra. he met Ali Rezai at a round-table conference and they bonded on sight, rather as Daniel Barenboim did in his life-altering encounter with the Palestinian academic edward Said. From there on, both men trained themselves to think about music's impact on the mind. Welser-Möst prepares discs for Rezai to try out on his implant patients. Rezai has become more aware of the music of the brain. Something, you feel, has to come out of this.

I asked the two men separately what they thought was achievable and neither had a ready answer, knowing that they are on the thinnest of ice. The conductor mumbled a pat phrase about helping musicians to lead healthier lives, while the neurosurgeon talked about depression and autism as the likeliest long-term beneficiaries of their work. Both were scathing about the Mozart effect, which is claimed to produce cleverer babies and more efficient workforces. The continent they have landed on is still unexplored, except for one or two unavoidable features.

"Stress," says Ali Rezai, "can take 20 years off your life. Music can relieve stress. That could be a start."