Music Overhaul for Outland, pretty self explanatory.
Sound files used were taken directly from the Legion 7.3.5 Client.
Warlords of Draenor Soundtrack:
WoW Warlords of Draenor Soundtrack (Collector's Edition) - YouTube
Download Link:
Dropbox - Outland - Draenor Music Conversion 3.3.5.rar