I add music to the cover page for each chapter, but I don't add music to the page by page updates. First of all, I don't think I could find music that matches each page perfectly, and even if I could, most people would finish reading the page before the music even really got started. Since the covers don't have any text (other than the name of the chapter), I figure it's a happy medium. For people who like the music, it sets the mood for the chapter, and for those who don't like it (for whatever reason^.^) it's not a distraction to the story.
As a reader, I do have autoplay turned on/ I've found a lot of cool interesting music that way! If the music has words though, sometimes I'll pause it until I finish reading because hearing words while reading is hard for me.