Tolkien was a very strong Christian and in his wonderfully written "Silmarillion," the Old Testament to the New Testament of the Lord of the Rings trilogy, the opening chapters parallel the first book of Genesis creation ex nihilo.
In Tolkien's universe Illuvatar is the personal Divine Creator who sings the universe into existence from nothing. Here is the opening paragraph:
"There was Eru, the One, who in Arda is called Illuvatar; and he made first the Ainur, the Holy Ones, that were the offspring of his thought, and they were with him before aught else was made. And he spoke to them, propounding to them themes of music; and they sang before him, and he was glad...."
The themes of music became the world's creation. Illuvatar transformed the music into material reality.
As you probably know, Lewis credits Tolkien among others, with bringing him to Jesus Christ. During the years of his walk Lewis rethought everything he previously held as true. By the time he wrote the Narnia Chronicles Lewis embraced the literal and historical elements of Scripture beginning with Genesis. In the second book of the Chronicles, "The Magician's Nephew," Lewis beautifully illustrates the creation of Narnia from nothing as Aslan, his Christ figure, sings it into existence. As Aslan sings, all life forms arise fully formed, each after its own kind.