From the wiki (https://lotrminecraftmod.fandom.com/wiki/Thread:308819#160):
Do you think it would be possible to add an option to reverse the way the Music Pack creator works? Instead of adding a track and selecting the regions, selecting a region and add a list of tracks (with those already added elsewhere available instantly maybe)...?
From the wiki (https://lotrminecraftmod.fandom.com/wiki/Thread:308819#160):