What gives a piece of music its personality and feeling?
What makes a happy song a happy one? What are the elements that give this particular property to a music piece? Can a computer understand what is the feeling a song transmits?
This question is also valid for the rest of the human emotional states (i.e. sad, angry).
From talking to musicians, I found some theories but they don't quite resonate with me. I have heard that the type of emotion a song gives is determined by the key (D minor etc.) in which the song has been written. For example, the D minor key should represent a sad-ish song.
I am not much of a musician but from what I understood the key is the indication of the last note in the song. For me this is not so logical. How can a song's type be determined by a single note? It could be a convention but I don't believe this.
Another idea is that you could see if a song is more aggressive than others but there should be at least a couple of other properties because aggressive songs can be sad, happy, angry, etc.
What are your thoughts on this issue? What other methods to you know or might have thought of for determining the feeling of a song?
Can a computer understand our music?