here is an simple tutorial from me, an person who decided to use bandcamp versions of familyjules remixes:
first of all, add your tracks into custom music playlist. after that, calibrate songs to their BPM, and find the playlist in "mods" folder or something
after that, create a resource pack via customize >resource packs
now, create a folder called "music" in this resource pack.
after that, put all stuff from playlist folder into folder of your resource pack.
hopefully, you understood that, since english is not really my main language.