Tonality
The following is described in terms used in Western disciplines of music.
Music from the Ryukyu Islands uses tonal structure that is different in music from the main islands of Japan, in particular the intervalic content of the scales used.
The chief pentatonic scale used in mainland Japan, for example, uses scale degrees 1, 2, 3, 5, and 6, also known as Do, Re, Mi, So, and La in the Kodaly system of solfeggio. This structure avoids half step intervals by eliminating the fourth and seventh scale degrees.
In contrast, music from the Ryukyu Islands is abundant in the half steps. Common structures used in Ryukyuan music are a pentatonic scale utilizing scale degrees 1, 3, 4, 5, 7, or Do, Mi, Fa, So, Ti, or a hexatonic scale with the addition of the second scale degree, 1, 2, 3, 4, 5, 7, or Do, Re, Mi, Fa, So, Ti. Half steps occur between the third and fourth (Mi and Fa), and also the seventh and first (Ti and Do) scale degrees. In particular, the interval from 7 to 1, or Ti to Do is very common. A folk tune can often be recognized as being Ryukyuan by noting the presence of this interval.
Read more about this topic: Ryukyuan Music