This sheds some light on the Rock scene in Japan. You would never have thought that in Japan people listen to rock. This site offers some background info on when and how Japanese Rock started and how it developed over the years.
This page link is about the history of Japanese music. It speaks of the most prominent musical artists of a few time periods before the present. The info pertaining to these artists refers to their backgrounds and how they started and became popular. It also mentions a few of the most popular styles of music during those periods.