This is a deep question that many people ask themselves very sincerely and with a burning desire to know that answer. I’ve certainly asked myself this question many times and am finally beginning to understand some of the keys to the mystery.
One of the main factors is your past association with that music. Is it possible to be profoundly affected by something you’ve never even heard before though? Yes, I believe that it is. Music that is especially emotional or rousing can be very effective, even if you’ve never heard it before. But then, music that is beautifully peaceful or ethereal can also be quite effective the first time around. So there you go…!
The way that music affects people is very individual. We do know that hearing music that one likes causes certain brain chemicals or neurohormones to be released. If you hear something that you absolutely love and that has wonderful associations with the past, that’s the best of all worlds! Here is a piece that does that for me! I played this piece with a dear friend in the past and just hearing it makes me feel so happy and peaceful. Hope you enjoy it too!