The three long tracks on Terrestrials were initially cut in 2008, during a single, night-long recording session by Sunn 0))) and Oslo's shapeshifting ensemble Ulver. Over the next four years, the former's Stephen O'Malley and the latter's Kristoffer Rygg added various musical elements to the recordings, creating something that retained the cooperative, spontaneous spirit of the session, but also transcended it. On 2009's Monoliths & Dimensions, Sunn 0))) expanded their musical reach considerably, adding instruments, sounds, and spaces to their palette while never forsaking their spine-quaking trademark sound. Ulver has always been a shape-shifting group, from their origins as a black metal band to creating ambient soundtracks and rock records to delivering 2013's Messe I.X-VI.X, an unholy post-rock and classical meld with the Tromsø Chamber Orchestra. On 2014's Terrestrials, opener "Let There Be Light" commences with the most minimal of keyboard and string sounds with backmasked guitar in a single, gently pulsing drone that gradually expands itself to include layers of foreboding, wavering brass (Stig Espen Hundsnes). The music crescendos with Greg Anderson's thunderous bass and Tomas Pettersen's furious tom-toms. Anderson introduces "Western Horn," with O'Malley's guitar vamping on a single-note drone. Keys, ambient effects, and trumpet waft in and heaviness ensues. It's offset only by a melodic Fender Rhodes adding a touch of the perverse as feedback and squall rule the center and foreground. It remains still and brooding until brass and marimba make the tension nearly unbearable. Violins, O'Malley's shard-like guitar, and Rhodes introduce magnificent closer "Eternal Return." It simultaneously evokes droning raga and a spaghetti western score. Eventually, marimba, Anderson's rumbling bass, church organ, and sculpted sonics wind it out until a near-classical interlude commences with fluttering, then pulsing strings, a minimal hypnotic synth, and Rygg's near chanted vocal. They create a prelude to a minimal abstraction before the cut reconstructs itself into a beautiful, blackened drone before fading into silence. Those who enjoyed Monoliths & Dimensions should find Terrestrials accomplished, disciplined and, in its way, heavy as hell. It perfectly reflects both Sunn 0)))'s impenetrably emotional dark heart and Ulver's expertly crafted senses of drama and dynamic.