Interesting. I also have mostly soundtracks in my playlists, for when I feel like listening to music at all (usually to drown out distractions). It's all soundtracks of things I've watched and enjoyed, and puts me in the mood of the memory of the movie or TV show its from. The music itself doesn't do very much at all for me directly.
This mirrors my own experience exactly. I too listen to a lot of soundtracks, from movies or from video games that I have enjoyed. Although music doesn't provoke an emotional response on its own, it has an incredible ability to being back emotional memories.
For a similar reason, when choosing music to listen to, I generally listen to the same songs again and again - those which have a connection to my past. It is very hard to feel anything about a new piece of music.
This means that I may regularly listen to one track by a particular artist, but have no interest in any of their other songs. I don't even like listening to remixed or live versions of songs that I enjoy - they are sufficiently different that they do not evoke any memories and hence are uninteresting to me.
