Music is a method of communication and thought process that we have not mastered because of language and our current society. Music has been used since ancient times for almost any event, whether it's spiritual or otherwise - even when you're just trying to have fun! As you know words easily have the power to make you feel a certain way. If someone tells you that you look good, that creates a positive feeling and when someone yells at you, it creates a negative feeling. The same way when you listen to sad music you'll feel sad, when it's upbeat, you'll feel happy, etc. That's also why music links memories and feelings together so well. If you look into human behavior and the psychology of why we are who we are you'll understand this better. Today human use a lot of tools such as language, phones, email, ... twitter to communicate and that is the way we think - through language. What most people don't understand is that language is simply a tool and should not be tied in with the way you feel or think. The idea of meditation is to 'not think' but that means not think in language - in the way that you usually think. Since humans rely too much on today's tools to communicate, they never practice their other part of brain. Music activates another style of thinking and communication which I believe is what you are calling spirituality. And some other random thoughts: That's how you 'set the mood' with music, why you get energized when you're in a club or something, why music is used so much with drugs, and why classical music is said to make you smarter :)
Today the only kind of music that's being used globally for communication are the commercials that try to get you to buy something. Why do you think foreign - specially american rock - songs are illegal in most countries ;)
I like old fashion Rock n Roll the kind of Rock people used to dance to. I like to drive fast to old school Punk. I like to sing along to oldies, old school soul, power pop, and Indie Rock. I like to go on really long jogs and day dream while I listen Bach or Vivaldi. I could go on forever with this list because I live my life to a soundtrack always playing music for every activity in my life.
Music has connected with me on such a deep level, that it has become a part of me.
I still haven't given up the idea of a spirit, either, and I don't think I ever will.
I approach what I feel is a state of spirituality when I contemplate our universe, be it as small as the workings of components within the individual cell (thank you Richard Dawkins for "The Ancestors Tale"), or as vast as the visible (and yet-to-be-envisioned) universe itself. These are guarenteed to bring out the "WOW" in me.
As for a favorite composer - well, my passion is woodturning. I have fitted my house with wireless speakers, so I can pump the iTunes down to the workshop. If I am roughing out a piece of hardwood, it's heavy metal. Currently, I listen to Sabaton, from Sweden. Their music fits well into my chosen (military) profession, and the idea of metal music (to me) fits well when the chips are flying.
For putting on the final finishing cuts, it's always Mozart. Nothing that I do (by myself) brings me a feeling of inner peace like running the cutting edge over the surface of a spinning piece of birds-eye maple, and watching the feathery shavings reveal the beauty within, while one of Mozarts' smaller pieces (no symphonies here, please) wraps itself throughout the shop.
Sheer freakin' bliss.