Hearing the Nether, End and Boss Music
Dimension and boss tracks are separate from the biome and time system, so they can work even when your overworld music seems stuck.
Dimension Tracks
When you travel through a portal, Reactive Music switches to the track assigned to that dimension. The Nether and the End each have their own selection, so you should hear a distinct song the moment the loading screen clears. If you still hear overworld music, you are likely standing in a modded dimension that has no mapping — those fall back to the default pool.
Boss Music
Boss tracks are triggered by the fight itself, not by the dimension. When a major enemy engages you, the pack swaps to a dedicated battle theme and returns to ambient music once the fight ends. This works with vanilla bosses and with Cobblemon boss encounters, which is the main reason people pair this pack with that mod.
Troubleshooting
If boss music never plays, confirm the boss category is enabled in the Reactive Music config and that no override track is forced globally. Some custom bosses from other mods are not recognised as boss entities, so they will not trigger the theme — that is expected behaviour, not a bug. Reload the pack after any config edit.