The Ainulindalë (Quenya: [ˌai̯nuˈlindalɛ ]; "Music of the Ainur") is the creation account in J. R. R. Tolkien's legendarium, published posthumously as the first part of The Silmarillion in 1977. The "Ainulindalë" sets out a central part of the cosmology of Tolkien's legendarium, telling how the Ainur, a class of angelic beings, perform a great music prefiguring the creation of the material universe, Eä, including Middle-Earth.The creator Eru Ilúvatar introduces the theme of the sentient races of Elves and Men, not anticipated by the Ainur, and gives physical being to the prefigured universe. Some of the Ainur decide to enter the physical world to prepare for their arrival, becoming the Valar and Maiar.