I remember not really noticing WoW's music while playing the game, but once I turned it off I felt something is missing. Some melodies are actually independent, wonderful background/ambient pieces - for example:
Mulgore day & night (Tauren starting area) - https://youtu.be/4cFj8eaD0zs
I'm feeling strong nostalgia while listening to this <3 ...unfortunately, the game moved on from what I liked playing once, long time ago.