Most of the trailer music on YouTube, specially RSM, has the style of the music next to the title. e.g.: Epic Dark Choral, Uplifting Battle, etc...
And I was wondering, who define those? Are those "subgenres" defined by the composer when they write the music, or do they really exist?
I'm curious if there's a guideline on what makes each of those subgenres and how to write a track in that style, or not.