Kino has what we might call an "ancient soul." He is connected in some mysterious way to the distant generations of his people when they were song makers.
His people had once been great makers of songs so that everything they saw or thought or did or heard became a song. That was very long ago.
Steinbeck is ambiguous in his description of how the other people of his village relate to these songs. When speaking about Kino "listening to his music," Steinbeck says both "Perhaps he alone did this and perhaps all of his people did it," and "The songs remained; Kino knew them." So it's difficult to know if Kino's mysterious connection ("perhaps he alone did it") is unique to Kino's ancient soul and if the Song of the Pearl and the Song of the Enemy mean to Kino what they mean to others in his village.
When considering what the Song of the Enemy, one of the earliest songs we encounter, means to Kino, it is important to notice a subtle comment made by the narrator. When talking about the songs and saying "Kino knew them," the narrator also says, "no new songs were added." When Kino confronts the scorpion, seeing it above his baby's hanging cradle, the narrator says, "In his mind a new song had come, the Song of Evil, the music of the enemy ...."
In another aspect of ambiguity, when Kino hears the Song of the Enemy after his baby is stung, we are not explicitly told whether that too is a new song. Since "the music of the enemy" is so closely tied to the "new song" of the Song of Evil, it can be inferred that the Song of the Enemy was equivalent to "the music of the enemy" and that the Song of the Enemy was a second new song.
If this inference is upheld, then the meaning of this song to Kino is multidimensional. He has broken through the recent ancestral silence and erupted in a new song, indeed, two new songs, bringing the old ancestral song making back into current life. If this is correct, then the tragedies that Kino experiences and loss of focus his life undergoes might be seen as having been precipitated by breaking the silence surrounding the creation of new songs. It was a song not known by the people; it was a song he alone knew, but it was bigger than a personal song. It may have been a song that interrupted the fabric of life, just as the pearl later breaks the fabric of life again.
So to Kino, the Song of the Enemy means broken cords (or chords) of life. The cords or chords of life tying him to his people are broken. The cords/chords tying him to his son are broken. The fragile cords/chords tying Coyotito to his family, his people, and his own life are broken. The Song of the Enemy means loss, destruction, disconnection and rage to Kino.
Song of the Pearl
The meaning of the Song of the Pearl That Might Be to Kino was a secret meaning, a secret plan, a secret wish and expectation.
But in the song [of his people] there was a secret little inner song, hardly perceptible, but always there, sweet and secret and clinging, almost hiding in the counter-melody, and this was the Song of the Pearl That Might Be, for every shell thrown in the basket might contain a pearl.
In a sense, this song meant danger to Kino for he thought it unwise to make plans: "Kino knew also- that the gods do not love men's plans, and the gods do not love success ...." The song, a hidden melody in the continual, known song of the people, represented a hidden, secret plan that Kino both harbored and cherished. This song also meant fear, for he feared the consequences that would come if his secret song were to come out and become known or if, indeed, his secret song should be realized and he should find the pearl: "A plan is a real thing, ... A plan once made and visualized becomes a reality along with other realities."
Kino was right to fear finding the pearl because, when he found it, his pearl went into everyone's dreams and "he became curiously every man's enemy." In another sense, the Song of the Pearl That Might Be means hope and promise and goodness to Kino. If he were to find it, if he were to successfully sell it, if he were to successfully use that money for the good of his family, then all his dreams would come true. Conversely if he fails, he will be ridiculed, which adds to his fear: "neighbors would say, 'There it started. A foolish madness came over him so that he spoke foolish words. God keep us from such things.'"
The songs function as almost a physical embodiment of the emotions that Kino is feeling at that particular time and place. The songs do not occur all of the time and Kino is not hearing them at all hours of the day and night. Kino hears the songs in his head only when he has a powerful feeling or instinct, and the song he hears coincides with the emotions he is experiencing. For example, when Kino wakes up in the mornings with his family he hears "The Song of the Family," but when he feels he or his family may be threatened he hears "The Song of Evil" and the "Song of the Enemy."
The songs do point to a rich and important oral tradition for Kino and his culture's tradition. The songs are likely passed down from generation to generation and are likely an important part of growing up. If they weren't, the songs wouldn't come to Kino's mind so quickly and effortlessly.
The songs bring Kino a sense of familiarity and serve as a reminder of his old culture. The songs are also important for they foreshadow what is about to happen in the story. The songs also contain indescribable emotions in them that causes Kino to be startled by them.