Abruptum had already made a name for themselves in the early 1990s with their debut, as a melding of dark ambience, noise and black metal. 'Obscuritatem advoco amplectère me' was a 50 minute suite of utter chaos split into two halves, whereas their second album 'In umbra malitiae ambulabo, in aeternum in triumpho tenebraum' follows the same formula, except it's a single undivided 60 minute track. Flowing as an improvised piece of sound chaos, the album is challenging, anti-conventional and pretty structureless. For what it is though, it's one of the best instances of improvisational black metal around.
Pulling it apart, there seems to be a sense of cohesion to it, despite it sounding mostly improvised; well timed screams over cathartic drum beats, violin screeches that accentuate the feeling of dread. If this already sounds too 'out there' or unconventional for you, it probably is. I think this sound exercise struck me most prominently as a low-fi soundtrack, but very difficult listening because of how much it strays from convention, and has long periods of time where nothing remotely constituting musical competence happens. I enjoy it, time to time, but it's definitely a difficult listen, no matter how you put it.