Insen scale
Insen is a tuning scale adapted from shamisen music by Yatsuhashi Kengyō for tuning of the koto. It only differs from the hirajoshi scale by one note.
In D mode it consists of: D-E-G-A-C so it has the same notes as the Phrygian chord.
Other chords compatible with insen scale include M7♯11 when the scale is played half steps lower and Cm6 and Cm when the scale is played one full step above.
In India's Carnatic music, this scale corresponds to Revati.
Other scales related to koto instrument include the Hirajoshi, Iwato and Kumoi-choshi scales.
