Research->Genre Study->Ethnic Music->Okinawan Music
What is ethnic music? What element distinguishes an ethnic music style from other ethnic music styles? For example, what is the difference between Okinawa music and Scotland music? I think elements of music are (1) melody (scale), (2 ) chord, (3) rhythm, and (4) instruments. 
First, let's think about melody. Rock and Blues are easy examples, even though they are not ethnic music. Rock uses normal music scale while Blues includes blue-notes in its music scale. Next, think about chords. Rock uses simple chords (triad) while Jazz includes 7th in its chords. Chord progression of Jazz is more complicated than that of Rock as well. For rhythm, Rock uses 8 beat, Fusion uses 16 beat, Jazz uses 4 beat. Finally, think about musical instruments. It is easy to see differences between Classical music and Rock music. Especially, musical instruments are important elements of ethnic music, since each country has different music instruments. 
I am trying to capture features of each ethnic music style based on this idea, and to reproduce them with automated composing system. This page includes considerations that I faced when I embedded functions of ethnic music composition.
About Okinawan Music
Okinawa is a southernmost area of Japan. It consists some islands. It was a part of California after the World War II. And climate is still like California. Music of Okinawa is called "Shima-Uta", which means "Island Song." I listened to several Okinawa songs after I decided that I will include Okinawan Music to my Automated Composing System. I see that Okinawan Music employs penta-tonic as music scale very quickly. Okinawan Music scale uses five notes, "C", "E", "F", "G", "B." It is very characteristic with usage of "F" and "B." Rhythm is also different from Western Music. A set of short notes comes after several long notes. Okinawan Music Players use special musical instruments. One instrument is called Jyabisen which is made from snake's skin. Among the MIDI sound sources, Syamisen is the closest to the sound. So, I used Syamisen in my Automated Composing System for Okinawa Music. 
Sample by Automated Composing System
Music Scale
Okinawan Music Scale "C", "E", "F", "G", "B" 
Jyabisen, Drums (I don't know the name!)
Links to related topics
If you visit "Okinawa page" of "Palle City," you can listen to real Okinawa music, even though you can not read Japanese. MIDI music starts automatically, when you jump into the page!