When is the sfx .wav file "wermusic" used?

I dont know, but, test it^^

When the player respawns.

Thats not when the player respawns, that particular sound effect is called spawn. I hear it in game but cant pinpoint what triggers it.

Spawn plays on the intial spawn in a server, or of that once you have changed to a different team. Wermusic is the .wav played for every respawn thereafter.