If you are not sure what this is all about, reference to this post, please, which hopefully explains why the following sounds familiar.
In the beginning, the One created little gods from his thoughts - probably because he was lonely, or possibly because he had a cunning plan. Because they were little gods they already knew quite a lot, so the first thing he had to properly teach them was how to make music.
And he taught them a song and all the little gods sat together and made music and the One leaned back and enjoyed the show. One of the little ones, a guy called Melkor, wanted to show off and started playing a solo. Some of the other little gods got confused and didn't quite stay in tune, some others didn't like it and stuck to the original song. The One laughed and made them start a new song and again Melkor went to show off. And this repeated for a bit with the One inventing new songs and Melkor going on to show off.
After a while, the One had had enough and told everyone to stop. He showed them that their music had created a whole planet to live on - with elves and humans and all sorts of things on it. Some of the little gods wanted to create their own things, but they all found that Melkor had somehow fiddled with their part of the song (one of them singing of water, the next of air and so on) and made it more scary than they thought it should be.
The One started the world and some of the little gods went down onto it. They found it was not as beautiful as it had been described - they sort of fell for the IKEA model of a world. It still needed assembly.
Even though it was still a lot of work, Melkor (like a member of management) wanted the world for himself. And he said "I did something to create this, I wanna keep it!". The other little gods said "No way! We sung as well, we'll share it!" and Melkor stalked off into the void of space and sulked.
As soon as he was gone, the others decided to start working properly. They started building all sorts of things, like mountains and lakes and rivers and grass (because they were gods, obviously, not just working people). Melkor got a bit fed up when he saw them having fun and returned from his sulking spot to stomp on everything they had built. A bit like a naughty kid in the sandpit when everyone else is building sand-castles.
So they had a big fight scene, but because there was no elves or humans around yet, no one noticed.
2 days ago