The line is missing the particle и:
а без музыки И на миру смерть не красна.
на миру и смерть красна means that if you are not alone, even death isn't that scary. Particle и emphasizes the word that follows (и смерть = even death).
Tsoi modifies the line a little bit, moving the emphatic "и" ("и на миру смерть" instead of "на миру и смерть") and adding negative "не", which becomes "without music, death is terrible/scary/etc even if you are not alone / even if you are surrounded by people".