“Elwë Singollo came never again across the sea to Valinor so long as he lived, and Melian returned not thither while their realm together lasted; but of her there came among both Elves and Men a strain of the Ainur who were with Ilúvatar before Ea." - Of Thingol and Melian
“Moreover it is doom that the Firstborn shall come in the darkness, and shall look first upon the stars... Long they dwelt in their first home by the water under stars, and they walked the Earth in wonder." - Of the Coming of the Elves and the Captivity of Melkor
"...and Yavanna returned to Aulë; and he was in his smithy, pouring molten metal into a mould. 'Eru is bountiful,' she said. 'Now let thy children beware! For there shall walk a power in the forests whose wrath they will arouse at their peril.' 'Nonetheless they will have need of wood,' said Aulë, and he went on with his smith-work. “ - Of Aulë and Yavanna
“But to the Atani I will give a new gift.’ Therefore he willed that the hearts of Men should seek beyond the world and should find no rest therein; but they should have a virtue to shape their life, amid the powers and chances of the world, beyond the Music of the Ainur, which is as fate to all things else;” - Of the Beginning of Days
Valaquenta begins with a short summary of Ainulindalë. It then goes on to introduce the Lords and the Queens of the Valar, giving a bit of background information on each of them and explaining how they relate to one another.
Next, we are introduced to the Maiar, spirits similar to the Valar but of a less degree. The last section is titled 'Of the Enemies' and explains a bit more about the cruelty of Melkor as well as introducing his servant Sauron.
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 Waldman letter is a letter written to Milton Waldman, an editor and advisor to publishers in London, who had expressed and interest in The Lord of the Rings and The Silmarillion after the widespread success of The Hobbit. For context, The Hobbit was published in 1937, this letter was written in 1951, and The Fellowship of the Ring would not be published until 1954.
