There are only a little more things out there, which mesmerize myself more than World Of Warcraft's Original Soundtracks. One thing is in any case Instrumental Live Versions of these OSTs.
My favourite one is the main theme from good ol' WotLK (Wrath of the Lich King), which you were able to listen to during the WotLK Login Screen. And you know what? The glorious Game Music Ensemble at UCLA performed a orchestral version of it on the 17th of May 2017 in Schoenberg Concert Hall.
Source: Game Music Ensemble at UCLA
Originally composed by the famous Russell Brower in 2008, the WotLK OST gained (and gains!) lots of postive feedback. For someone who played WotLK it was clearly a memorable scene, when you first reached Dalaran or you arrived at Howling Fjord or Borean Tundra.
So check it out! It is clearly oooooutstanding! :) CLICK ME
And if you are more into choirs, I highly recommend the "Invincible" soundtrack as a live version. CLICK ME