The Ainulindalë (Q.: "Ainu-song–"), also called the Music of the Ainur, the Great Music, the Music, and the Song, were the divine chords sung by the Ainur. It was the development of the three themes of Ilúvatar and thus an expression of the divine order.
The second theme, probably indicating the shaping of Arda, defeated Melkor's discord and incorporated it into itself.
- Foster, Robert. The Complete Guide to Middle-earth.