Out of print for over 15 years, Altar finally returns on double vinyl!! The album is a collaboration between experimental music groups Boris and Sunn O))), originally released on October 31, 2006 through Southern Lord Records. In addition to the main groups: Sunn O))) and Boris, Altar also boasts an extensive roster of guest musicians/collaborators such as Dylan Carlson, Kim Thayil (Soundgarden), Joe Preston (Earth, Thrones, Melvins, High on Fire), Phil Wandescher, Bill Herzog and Jesse Sykes (all of Jesse Sykes and the Sweet Hereafter) as well as long time Sunn O))) collaborators TOS Niewenhuizen and Rex Ritte.