The Altar album is not a split album. Altar is a collaboration album between Sunn 0))) and Boris that is a result of both bands conceptualizing, writing and recording the album together as one entity. Both groups have stepped outside their previous sounds and created a wholly unique album that stands on its own unique ground. There are elements of each groups trademark sound within the album but true to each groups progressive and experimental aspects, Altar moves into a completely new dimension. Also contributing additional entrancing textures are the guest collaborators on this album including Jesse Sykes (vocalist:Jesse Sykes and the Sweet Hereafter), Kim Thayil (Soundgarden), Joe Preston (earth, thrones, melvins, high on fire) Bill Herzog, Phil Wandescher (Jesse Sykes and the Sweet Hereafter), Rex Ritter (Jessamine, Fontanelle), Tos Niewenhuizen (Beaver, GOD), and Steve Moore (earth). And certainly not last or least, Dylan Carlson plays on the vinyl only exclusive track "Her Lips Were Wet With Venom". The tones, emotions, and energy that lurks within Altar is beautifully ominous. It is a very bold statement from both artists that will not only appease the present cult following but brazenly induct new devotees.