The folders where you can place files have an example file in them, make sure to remove all example files in all folders in your final version. Name your music files the same as the examples, numbers can go from 1-10 at the end of the file.
When creating a zip file out of the folders make sure that within the zip file the top level folder is "assets" and the pack.mcmeta.
Remember to enable the resource pack in game under resource packs.
For more information about resourcepacks check out the wiki: https://minecraft.wiki/w/Resource_pack