Well, some cultures use music to put themselves to trance state. That's true. But we all are not in the position to debate on why they do that. It's their believings? Maybe a way to be closer to God?
I will also not deny that music can create negative influence. This is the part where I worte about becoming frenzy. Techno Music, where 180 bpm (beats per minute) are usual can already have a negative influence on teenies.
But IMO, it is not the music which creates the violence in that case, but more the lyrics, which go with.
Aha, so why we always say 'heart-beat' and not 'heart-sound' ? Of course the heartbeat can be considered as a music, maybe monotone, but it is a 'rythm'