If I just want to relax I listen to some of Fytch's work. http://www.youtube.com/watch?v=y8Pag-NPJE8 I don't know, just some of it lets me calm down and think Also Sybreed has some relaxing songs.
Usually around five too seven hours....maybe ten if I am being lazy. For the last 5 days or so I have only been getting around 1-3 hours due to stress.