The fierce battle between Daniel Barenboim and Christian Thielemann to become the one true leader of the Berlin opera scene was a tragic but inevitable conflict made necessary when the city decided that it could no longer afford to fully subsidize three full-time opera houses, says Martin Kettle. But Barenboim/Thielemann is more than a faceoff between two great artists scrapping over a common pool of money: it is a clash of ideologies, both musical and political. It is liberal versus conservative, innovator versus traditionalist, and Berlin is caught in the middle.