Yet these sounds, subtle as they are, have a sense, a logic, an order of their own; and if we can only learn how to approach them, we can get at this inner orderliness that makes them into "music." The process of perception which we have to learn here is somewhat akin to certain more familiar processes. For example, what comes to our eyes from the outer world is simply a mass of impressions of differently colored and shaped spots of light; only gradually, as we grow out of infancy, do we learn that one group of these spots of light shows us "a house," another "a tree," and so on. Similarly words, as we easily realize in the case of a foreign language, are to the untrained ear mere isolated sounds of one kind or another; only with practice do we learn to connect groups of them into intelligible sentences. So it is with music. The sounds are at first mere sounds, separate, fragmentary, unrelated. Only after we have learned to group them into definite melodies, as we group spots of lights into houses or trees, and words into sentences, do they become music for us. To approach sounds in such a way as to "make sense" of them--that is the art of listening to music.
The first step in making sense of any unfamiliar thing is to get quite clearly in mind its central subject or subjects, as, for example, the fundamental idea of a poem, the main contention of an essay, the characters of a novel, the text of a sermon. All music worthy of the name has its own kind of subjects; and if we can learn to take note of, remember, and recognize them, we shall be well on the road to understanding what at first seems so intangible and bewildering.
A possible confusion, due to the use of terms, must here be guarded against. The word "subject" is used in a special sense, in music, to mean an entire theme or melody, of many measures' duration--thus we speak of "the first subject of Beethoven's Fifth Symphony," meaning the entire contents of measures 6-21. Now this is obviously a different meaning of the word "subject" from the general one we use when we speak of the subject of a poem or a picture, as the fundamental idea about which it all centers. This long musical "subject" all centers about a little idea of four notes, announced in the first two measures of the symphony: