If music in general is an imitation of history, opera in particular is an imitation of human willfulness; it is rooted in the fact that we not only have feelings but insist upon having them at whatever cost to ourselves. The quality common to all the great operatic roles, e.g., Don Giovanni, Norma, Lucia, Tristan, Isolde, Br?nnhilde, is that each of them is a passionate and willful state of being. In real life they would all be bores, even Don Giovanni.