It won’t surprise me if neuroscientists eventually succeed in unlocking the mystery of music. I don’t fear that prospect, but I do have a sneaking suspicion that part of the charm of music lies in the fact that we don’t know what it means, any more than we can explain the equally mysterious charm of a plotless ballet by George Balanchine or an abstract painting by Piet Mondrian. “We dare to go into the world where there are no names for anything,” Balanchine once said to Jerome Robbins. Most of us, on the other hand, live in a prosy, commonsense world where everything has a name and most things have an explanation. That’s why it is so refreshing to enter into the presence of great art, and why the greatest works of art always contain an element of ambiguity. A masterpiece doesn’t push you around. It lets you make up your own mind about what it means —- and change it as often as you like.