Like some cosmic demon descending to Earth in an H.P. Lovecraft novel, the music of ORANSSI PAZUZU tests the sanity of mere mortals. Conjuring a miasma of psychedelic black metal and a particularly unsettling brand of dark ambience, the Finnish band pairs a fearlessly idiosyncratic and progressive sound with a knack for the conceptual. Its 2024 album, Muuntautuja (“Shapeshifter” in English), was a snarling and epic tale of cosmic horror, filled with churning soundscapes and ice-cold synthesizers. Oranssi Pazuzu’s North American tour brings them to the Stone Church in Brattleboro on Wednesday, May 27. Denver’s WAYFARER provide support.