Tim Hecker’s upcoming seventh album is preoccupied with purity. First, there’s the title: Virgins. Then, there’s the sound, which melds Hecker’s unique brand of ambient abstraction with “restrained composition recorded live,” as per a press release. Now, there’s the official video for “Black Refraction” — a hazy short that takes place in some kind of church. The specifics aren’t there since the picture is fuzzed-out and overexposed, but it is clear that there’s a group of people worshipping, watching what looks like a smoke-filled urn swing back and forth over the sacred space. Created by artist Sabrina Ratté, the video moves in synch with Hecker’s song: When the hypnotic piano repeatedly fades out and then cuts back in, the visuals do the same, looking increasingly warped and burnt with each flash.