The band has been known by several monikers since it was established, originally being known as Tenth Level Tauren Chieftain, level 10 being the highest level a Tauren chieftain hero could be in Warcraft III : Reign of Chaos and its expansion.

The name was changed to Level 60 Elite Tauren Chieftain for BlizzCon 2005, level 60 then being the highest level attainable in World of Warcraft. The band was later dubbed Level 70 Elite Tauren Chieftain following the release of World of Warcraft's expansion, The Burning Crusade, as The Burning Crusade raised the game's level cap to 70.
They have since been renamed their current title, Level 80 Elite Tauren Chieftain, to comply with World of Warcraft's upcoming second expansion, Wrath of the Lich King, which once again has raised the game's level cap to 80.

On July 16th 2007, the band, then known as Level 70 Elite Tauren Chieftain, released their second song, "I Am Murloc." On August 4th 2007, at the year's BlizzCon, the band performed two new songs, "Rogues Do it from Behind" and "Terran Up the Night."

On June 29th 2008, at the Worldwide Invitational in Paris, France, Level 70 Elite Tauren Chieftain performed "Power of the Horde," "Rogues Do it from Behind," "Terran Up the Night," a new song, "Raise Some Hell," referring to Blizzard's newly announced development of Diablo III, and "I Am Murloc." After each song, the band "leveled up" twice, before ending their set as Level 80 Elite Tauren Chieftan.
The band has yet to release any studio recordings under their current name.

Source : http://www.wowwiki.com/Level_80_Elite_Tauren_Chieftain