When turning down the dialogue volume, dialogue in cut scenes is not affected, which you would assume would happen.
When turning down the music volume, some* music effects are not affected, which you would assume would happen.
Why is this? They seem to both be treated as “sound effects” instead of the logical option.
I find this annoying since I often play PvE with music and dialog off, while having the sound effects on, since I like to listen to my own music in the background or watch some shows. But playing without sound effects is weird and also I want to hear the shooty boomy!
*The music in the background of Attikus and the Thrall Rebellion dialog scenes, at least.