Why does the music seem to "let go a million moths all over the dusty furniture and swan-neck shadows and in our bones"?

Spare prose makes it seem like Esperanza is speaking directly to us a friend: "There is a junk store. An old man owns it. We bought a used refrigerator from him once." The technique of building one detail upon another connotes an excited child's retelling of an event.

The elusiveness and unobtrusiveness of the old man is symbolized by the personification of his "pair of gold glasses floating in the dark." Similes "like all of a sudden he let go a million moths," "like water," and "like marimbas only with a funny little plucked sound to it like if you were running your fingers across the teeth of a metal comb" reveal Esperanza's unique and colorful imagination. The metaphors "swan-neck shadows" and "in our bones," for example, let the reader see and feel how deeply the sound of the music penetrates.