There are many ways you could go with this - for example its characteristics as shown here in the anchor chart used in my good friend, Mrs. Chandler's music room. One might also list typical instruments used in folk music and or examples of folk music learned in class. Or perhaps those could be companion anchor charts used in later lessons.
Awesome job Mrs. Chandler and you know I'll be stealing this excellent idea next week with my own students!!! : ) You can see Mrs. Chandler's blog here