Guide to the Silmarillion: Ainulindalë
Ainulindalë: The Music of the Ainur
It is in this chapter that we see the creation of the world through the music of Eru Ilúvatar and the Ainur, the beginning of the unrest of Melkor, the descent of the Valar into the world, and the first battle of the Valar against Melkor.
The Music of the Ainur
There was Eru, the One, also called Ilúvatar, the creator God of Tolkien’s myth. He made first the Ainur, the Holy Ones, which are angelic beings and have been called gods. Ilúvatar spoke to the Ainur, teaching them in song, and they sang before him. First alone, next together. Ilúvatar introduced the first theme, and there was harmony for a time.
Melkor, greatest of the Ainur, altered his part in the music in an attempt to increase his power and glory. Discord arose among the Ainur. Ilúvatar began a new theme (the second theme), but Melkor contended with it. Then, a third. Finally, Ilúvatar arose and ended the Music entirely.
Ilúvatar showed the Ainur a vision: the world and its history unfolding. “Behold your music” — for through it was the world made. In the vision, the Ainur saw the Children of Ilúvatar, and they loved them. Many desired to go down into the world and prepare it for the Children; Melkor desired to rule over them and be called “Lord”.
The vision ended but Ilúvatar then spoke the world into being. Some of the Ainur chose to go into the world — they are called the Valar. The Valar then began the long work of preparing the world for the Children, all the while Melkor meddled in their plans.