Jazz doesn't relax me. It stimulates me, even the slower stuff. Just something interesting in all the changes and evolutions the music takes.
Honestly, late 70's and early 80's music realxes me. Yes I mean that mishmash from rock to disco to pop to new wave, all that stuff relaxes me. It takes me back to my younger days when I had no cares except hoping the next song on the radio was one of my favorites, and my mom wouldn't find my stash. You'll have to imagine what my "stash" was.
Well, except for Black Sabbath, that was never very soothing, but then again I always liked taking the crazy train now and then. And that had nothing to do with my stash, btw. Just my mood.