I can't really narrow it down. I listen to:
- folk music, (blues, bluegrass, etc., not so much "contemporary folk" music, although I do have a Simon and Garfunkel CD)
- oldies from the 50s and early 60s, (I don't care for much RnR after 1964)
- some big band,
- some jazz (yes, I occasionally listen to WYSU for this, don't like "smooth jazz" aka elevator music, and WYSU doesn't play that kind)
- finger-picking acoustic guitar music, (mostly Leo Kottke, but there are a lot of great artists out there)
- when listening to modern music, I stick to alternative rock that sometimes--but not always--has a "retro" feel.
There is more, but this is what comes to mind at the moment.