Echoes of War is a Blizzard Entertainment-produced orchestral version of the music from their three most popular video game series, World of Warcraft, StarCraft, and Diablo.
It includes previously unreleased theme music from StarCraft II: Wings of Liberty, Diablo III, and World of Warcraft: Wrath of the Lich King.
In addition, the Legend Collector's Edition also contains an extra DVD, which includes behind-the-scenes content including Japanese composer Kow Otani talking about work on Diablo III, as well as a 32-page color booklet and nine exclusive postcards.
The album was inspired by previous iTunes sales of World of Warcraft music tracks.
The track received much unexpected support from players, so Blizzard Entertainment worked to create an album of music.