Does anyone know of a good description of alle the different genres and subgenres of music that there are and their names?

The reason I ask is that I'm finding it very difficult to place each song in the correct category/-ies. Of course you would be correct in saying that it doesn't matter what I call them as long as I can find them and they're arranged according to my personal tastes, but nevertheless the perfectionist in me really wants to know how to decide, as far as possible, in what genre(s) a particular piece of music belongs...