I was intrigued by the leading question of this thread - then I read the content and it seems to have wandered around a lot of different subjects... that being the case, I thought I'd chime in!
I certainly think you have to have an interest in music to enable the possibilities. I had a brother who sang (sadly no longer with us), another who plays drums, a sister who plays guitar and I attempt to compose and produce. However, our interests in music have always been disparate - jazz and soul, heavy/thrash metal, electro, etc. What I do think binds us is the ability to deeply appreciate music in all genres - and not just on a superficial level.
I've responded to quite a few
"what do you think of my new track..?" posts on this forum by listening - I mean
really listening - to a track and eeking out parts that stand out or just don't quite sound right. To have a deep appreciation of music, you have to be able to allow yourself to become immersed in it - and that is an ability that few can appreciate, let alone nurture.
There are so many factors in determining "ability" - aside from whether it is genetic, that the question has (obviously!) become a debate. Possibly mis-using an old adage, I'd say you need to have music
in your blood to really make a go of it. I'm not at all trained, I can't play any particular instrument, but I have a passion for music that borders on addiction - and that, for me, plays a very large part.
One other aspect, I think, is disposition. If, like the majority of a population, your day consists of "sleep, eat, work, repeat" then it is unlikely that you will find harmony enough to nurture any inate skills you may have in music. If, on the other hand, you find yourself hunched over a keyboard (or Reason!) at 3am on a Tuesday, struggling to find the last 4 bars of your latest track, then you've got
something...
Thanks for the healthy debate!
aggie