This movie wanted to say that music is not for pastime,in fact music has impact on our life and gives us any feels such as happy, sadly, hopefully, depression, lovely, stresstion even (fear) and it's could be dangerous because humans don't have enough acumen for understand some things
In fact, sometimes they find things that their souls don't has capable of knowing.
And for this reason the humans spirit is possible be depressed and even he can't understand him/herself