I was once general practitioner-cum-neurologist to members of a famous string quartet. They taught me many things. For example, ‘If you listen carefully to a live performance, why is the music sweeter in the second half of a concert?’ I ignorantly suggested that perhaps the musicians were now more relaxed or had adjusted their instruments according to the concert hall acoustics? No, I was firmly corrected. It was because they always insisted that their fees should be paid during the interval. I was told that when musicians are on the international circuit, in certain foreign parts it was not unknown for the local impresario to disappear with the box-office takings. …