The one thing that can be said about music:  it exists necessarily.  It isolates existence, in a way, from appearance and all other entanglements.   

Of course there is an auditory aspect and a psychological aspect to these things.  But there is an auditory and and psychological aspect to any hearing.   

Music tends towards pure existence in its positivity.  As such it is the most reliable theophany there is.   Something is  activated  and activates.

Mulla Sadra proposes a logic wherein God qua pure act generates the divine names, in an act of primal negation, and then affirms those names in a secondary negation - without any effect whatsoever on God's own existence. 

God is the most existent thing there is.  Music is theophanic to the degree that it is able to yield a higher level of existence in the system in which it is interacting.   

What is the value of that? It is at higher levels of existence - near dissolution, that greater freedom is possible, and the veil of maya is partially rent.  

Music therefore has an imperative to maximize existence.   Higher existence in any system means freedom, wisdom and communication - it is in this state that new ideas suddenly emerge:  music gives birth to thought.   

Transcendental Black Metal is designed to yield thought in this way - and its techniques for this are the burst beat and general tremolo