There are three main songs in this book. 'The Song of the Family' represents the protagonists, Kino and his wife and son. 'The song of Evil/the enemy' denotes anything that threatens the security and happiness of Kino and his family. Finally, there is the music of the pearl which at first appears positive as it promises to bring wealth and freedom to Kino and his family.
To begin with the song of the pearl is part of the whole 'Song of the Undersea,' a part of nature that appears beautiful and beneficent. However, by the end, having brought nothing but misfortune to the family, its music becomes 'distorted and insane' (chapter 6), merging into the song of the enemy, of evil.
'The Song of the Family' also changes in the course of the book. At first it is gentle and soothing, but by the end it takes on a whole new quality as the family is left without support, cornered, hunted down.
The Song of the Family had become as fierce and sharp and feline as the snarl of a female puma. (chapter 6)
At this point, then, this song is figured as a fighting animal, full of rage and desperation as it struggles for survival.
Kino and Juana do survive, but only at the cost of losing their son and the former friendship of their neighbours. At the end they are depicted as being fundamentally alone, cut off from other human beings. Although they cannot undo the harm done by the pearl, they extinguish its evil music by casting it back into the sea.