Sunn O)))’s depth is, for some, their biggest attraction. Both in terms of sound – bowel-rumbling doom metal – and outlook: Kannon’s liner notes were written by critical theorist and performance artist Aliza Shvarts, who turned heads with her 2008 abortion-based work while studying at Yale.

On their first album since collaborating with Scott Walker on Soused in 2014, Stephen O’Malley and Greg Anderson are on a deep dive again. A triptych, inspired in part by the buddhist deity Guanyin Bodhisattva, Kannon is an immersive exercise in metal meditation and repetition. The first track – clocking in at 12min 50sec – sees them marry a creeping riff with growls and reverb-drenched snarls; the second barely lifts the pace, with feedback giving way to chanting and a high-pitched wail; the third gives more room to the guttural noises and screams that feel like pitched-down black metal.

It’s a daunting 30 minutes of music, but there’s something surprisingly calming about Kannon, something that hints at the hidden depths beneath Sunn O)))’s cloak-and-dagger routine.