During this time, Vikernes became a part of the early Norwegian black metal scene and met Mayhem guitarist Euronymous.

[9] According to a statement made by Vikernes on burzum.org, the master tapes for the version of "Burzum" meant for Hvis lyset tar oss were lost by the Norwegian prison system.

[citation needed] Filosofem was recorded under purposefully bad conditions in order to retain a raw lo-fi sound.

The first three songs are in the key of E minor, and all tracks of the album are quite long in duration (the shortest being just over seven minutes), being primarily composed around very few musical motifs.

"Burzum" ("Dunkelheit"), the opening track, features a prominent melody played by a synthesizer that sits atop the distorted guitars and vocals.

The front cover is named Op under Fjeldet toner en Lur (Norwegian for "Up in the hills a clarion call rings out").