Amalie Brunn, a.k.a. Myrkur, has turned heads as much for a predictable, snore-worthy cred uproar (she sang pretty, clean vox in an indie-pop duo, so she must be a false shithead hipster secretly snickering at black metal tenets) as her actual music (last year’s alternately evocative and raging seven-song self-titled EP). Her aesthetic reach is expanding on full-length debut M (due out on Relapse in a couple weeks). Brunn co-produces with Ulver mastermind Garm and doubles down on that counterbalance of disturbing, cooed melancholia and intense, blasting harshness. “Mordet,” her new single, offerss a little bit of both.