who has written a masterpiece entitled Essay on Composition, says, “It is the essence of composition that everything should be in a determined place, perform an intended part, and act, in that part, advantageously for everything that is connected with it.”15 In a composition, every part has its function. In a well-composed song each note is indispensable. In a painting, each line and hue is necessary. In a writing, each word is vital. The composer’s task is to create a unity (principle of principality),