I introduced one festival (ねぶた祭り) and one dance (阿波踊り） before. And Japanese traditional music was played there. Especially I think you could hear the sound of wadaico (和太鼓）. Wadaico is Japanese traditional drum. There are some Japanese traditinol instruments but wadaico is most famous and popular instrument in Japan. The other traditional instruments are koto(琴）、 shyakuhachi (尺八）、shou (鉦）、etc. Koto is like laid harp, shyakuhachi is like recorder, shou is like triangle.
The size of wadaico is various from big to small, and the playing style is also various from many player to one. The playing style by many people has a beautiful harmony, and the playing style by one person has strong sound.