It's great that you've written this piece detailing the significance music has to you, and the reasons why - I'm sure that many people could agree on the importance of their iPods or MP3 players as cherished possessions - however, I have to be really pedantic and point out that the word is "aesthetics", not "esthetics". Obviously I appreciate that English is not your first language, and everything else is spot on, so please don't take this minor criticism in a negative light.
I think that there's much to be said for "simple, obvious melodies" - sometimes more obscure genres tend to neglect this aspect - the "hook" of the song - because they disregard it as being too commercial. I think that this is a mistake, as the hook is obviously the most memorable aspect of any piece of music.
On the other hand though, I would purport that it's entirely possible for music to be both melodically memorable, AND mentally stimulating: for instance, one can write articulate, eloquent lyrics that are also extremely catchy.
Personally, I like music to be "clever", AND enjoyable, because then it can be appreciated on two different levels.
